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Page 1: An oficial publication of the Society for Conservation of ...14.139.252.116/Journals/2015 Vol 5 No. 1-2.pdf · Vechur Conservation Trust, Mannuthy, Thrissur Dr GS Brah Director, School
Page 2: An oficial publication of the Society for Conservation of ...14.139.252.116/Journals/2015 Vol 5 No. 1-2.pdf · Vechur Conservation Trust, Mannuthy, Thrissur Dr GS Brah Director, School
Page 3: An oficial publication of the Society for Conservation of ...14.139.252.116/Journals/2015 Vol 5 No. 1-2.pdf · Vechur Conservation Trust, Mannuthy, Thrissur Dr GS Brah Director, School

Chief Editor

Dr. B. Prakash

ICAR-CIRC, Meerut

Executive Editor

Dr. S.K. Niranjan

ICAR-NBAGR, Karnal

Editor

Dr. Indrajit Ganguly

ICAR-NBAGR, Karnal

Advisory Board

Dr MR JayshankarHead, AG & B, Veterinary College, Hebbal, Bangalore

Dr Sosamma IypeVechur Conservation Trust, Mannuthy, Thrissur

Dr GS BrahDirector, School of Animal Biotechnology, GADVASU, Ludhiana

Dr BP Mishra Joint Director Research, ICAR-IVRI, Izatnagar

Dr DK Sadana ILSI Centre, Model Town, Karnal

Dr CV Singh Professor (AG&B), GBPUA&T, Pantnagar

Dr SM Deb Director, ICAR- NRC on Yak, Dirang

Dr BK Joshi Ex-Director, ICAR-NBAGR, Karnal

An of�icial publication of the Society for Conservation of Domestic Animal Biodiversity

Editorial Office Animal Genetics Division, NBAGR P.O. Box 129, Karnal-132001 (Haryana), India For more information please visit www.nbagr.res.in

Published by Society for Conservation of Domestic Animal Biodiversity

Printer : Aaron Media, Karnal

Subscription (Annual) Indian Foreign

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Single copy Rs. 300.00 US $ 75.00

Page 4: An oficial publication of the Society for Conservation of ...14.139.252.116/Journals/2015 Vol 5 No. 1-2.pdf · Vechur Conservation Trust, Mannuthy, Thrissur Dr GS Brah Director, School
Page 5: An oficial publication of the Society for Conservation of ...14.139.252.116/Journals/2015 Vol 5 No. 1-2.pdf · Vechur Conservation Trust, Mannuthy, Thrissur Dr GS Brah Director, School

JOURNAL OF LIVESTOCK BIODIVERSITY VOLUME 5, NUMBER 1-2, 2015

Sikkim Black goats – characters, management and microsatellite based

genetic pro�ile

NK Verma, Pushp Raj Shivahre, Rak Aggarwal, Rekha Sharma, PS Dangi and

NT Bhutia

Genetic and phenotypic response to selection in various traits of IWH and

IWI strains of White Leghorn under long term selection

MC Kataria, A K Mishra, R K S Bais, S Kumar, Raj Narayan, S Johari and R Gopal

Low variability at Hinf I locus of major histocompatibility complex (MHC) –

DQB gene in Indian Mithun (Bos frontalis)

DS Gonge, S K Niranjan, S K Mishra, R K Singh, S Kumar and R S Kataria

Effect of different diets of full fat soybean (�lake) on the meat composition of

broilers

DS Rasane and SS Kamble

Tissue related in­silico mining of single nucleotide polymorphisms (SNPs)

from expressed sequence tags (ESTs) in livestock species

Neeraj Kumar Dhaliwal, Aruna Pandey, Birham Prakash, Avnish Kumar Bhatia

Production and reproduction performance of Red Sindhi cow

RP Jadhav and SS Kamble

Genetic evaluation of White Leghorn layers under reciprocal recurrent

selection

Ramesh Kumar, S Kalra, Satbir Singh and B Parkash

01

07

11

14

18

22

25

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Page 7: An oficial publication of the Society for Conservation of ...14.139.252.116/Journals/2015 Vol 5 No. 1-2.pdf · Vechur Conservation Trust, Mannuthy, Thrissur Dr GS Brah Director, School

Sikkim Black goats – characters, management and microsatellitebased genetic pro�ile

1 2N K Verma, Pushp Raj Shivahre , RAK Aggarwal, Rekha Sharma, PS Dangi, NT Bhutia , ICAR - National Bureau of Animal Genetic Resources, Karnal – 132001 (Haryana) India

ABSTRACT

Keywords : microsatellite, genetic diversity, goat 1 2

Present Address: Ph.D scholar dairy cattle breeding division ICAR-NDRI Karnal, Additional

Director, Department of Animal Husbandry, Dairying and Fisheries, Govt. of Sikkim, Gangtok

Corresponding author: [email protected]

INTRODUCTION

The goat population of Sikkim state of India is th

1,13,364 (19 livestock census, 2012) spread in all

the four districts. The male and females are almost in

equal proportion (53103 and 60261 respectively).

The study was planned to know the phenotype and

biometry of Sikkim goats. The visits were made to

North, East and West districts of Sikkim and

information on phenotypic and biometric traits of its

native goats were collected and analyzed. The �locks

seen during the survey consisted of black, white,

brown and mixture of these colours. The goats,

Singharey, with stripes on face extending from base

of horn to the muzzle mainly constituted the �locks

for which the phenotypic and biometric pro�ile has

also been studied (Verma et al. 2015a). Apart from

this, goats with jet black uniform colour were also

seen. These goats are distinct from Singharey goats

in respect of coat colour, type of horns and their size.

They look like Black Bengal but are bigger in their

body size and have longer horn. The phenotypic

traits of these goats were recorded by visual

Sikkim Black goats are distinct from Singharey goats, the main population of Sikkim state, in respect of coat colour, type of

horns and their size. Data on phenotypic and biometric traits was generated on 93 animals belonging to different �locks in

their native tract. Blood samples were collected from genetically unrelated animals. Sikkim Black goats are of medium

body size. Head is proportionate to body. Nose is straight. The horns are strong, broader at base, pointed tip, grey in

colour, curving backward. Muzzle is black, hooves are grey. Underbelly is also black. Beard is seen in few animals of both

sexes. These goats are slightly shorter than Singharey goats but their face, horn and tail are comparatively longer. The

mean estimates for height at withers, body length, Chest/heart girth, paunch girth, face length, horn length, ear length and

tail length in adult ( >18 months) female goats were 50.06±0.85, 58.75±0.73, 70.65±0.73, 79.57±1.17, 17.11±0.20,

10.17±0.53, 12.70±0.23, 10.35±0.24 cm, respectively whereas for males the average measurements were 54.70±1.19,

61.80±1.39, 75.97±1.48, 82.30±1.76, 17.90±0.29, 15.070±.77, 13.50±0.36 cm. The average body weight for adult females

was 28.48±0.72 kg and males 34.87±1.56 kg. Observed number of alleles varied from 2 to 9 with mean value 5.391±0.411,

effective number varied from 1.145 to 6.400 with mean 2.771±0.261. Observed heterozygosity (Ho) was less than the

expected (He) at most of the loci leaving ILSTS008, ILSTS005, ILSTS0087, ILSTS0029 and ILSTS034. The values ranged

from 0.125 to 0.882 with mean 0.420±0.038 for observed and 0.127 to 0.844 with mean 0.575±0.035 for expected

heterozygosity. Shannon's information index value varied from 0.291 (ILSTS029) to 1.950 (ILSTS030) with mean value

1.168±0.085. F estimates varied from -0.175 ( ILSTS087) to 0.835 (ILSTS058) with mean value 0.239±0.058. The

population also exhibited HW equilibrium w.r.t. ten loci where chi square values were non-signi�icant. A normal 'L' shaped

distribution of mode–shift test, non-signi�icant heterozygote excess suggested absence of bottleneck in the existing

Sikkim Black goat population. The study concluded that there was a reduction in genetic variability in Sikkim Black goat

population. Looking at the distinct phenotype but sharing the breeding tract with Singharey goats, there is a need to

conserve and propagate the population through appropriate scienti�ic management.

Volume 5, Number 1-2, 2015

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observation. Blood samples were collected from

possibly genetically different animals for estimating

the genetic diversity.

MATERIAL AND METHODS

The measurements orf different body traits viz.

height at withers, body length, Chest/heart girth,

paunch girth, face length, horn length, ear length and

tail length and body weights were recorded on 93 (

63 females and 30 males) animals. The body weights

were taken with the help of spring balance. Means

with standard errors were estimated to know the

average pro�ile of studied traits.

Genomic DNA was extracted from blood samples

using a standard phenol: chloroform extraction

method (Sambrook et al., 1989). A battery of 23

microsatellite markers based on the guidelines of

ISAG & FAO's DAD-IS program and used by us

(Aggarwal et al., 2006, Verma et al., 2007, Dixit et al

2010, Verma et al., 2015) for other goat populations

was utilized to generate allelic data. Microsatellites

ampli�ication was carried out using �luorescent-

labeled primers. The ampli�ied products were

analyzed with a DNA capillary sequencer ABI

Prism® 310 Genetic Analyzer (Applied Biosystems).

Gene AlEX software package (Peakall and Smouse,

2012) was used to calculate allele frequencies,

observed number of alleles, effective number of

alleles (Kimura and Crow, 1964), observed (Ho) and

expected (He) heterozygosity at each locus.

Polymorphism information content (PIC) value for

each locus was calculated by using the method

described by Bostein et al. (1980). Finally the

bottleneck hypothesis was investigated using

BOTTLENECK 1.2.01 (Conuet and Luikart, 1996).

RESULTS AND DISCUSSION

Morphological features of Sikkim Black goats are

shown in �ig. 1. They are of medium size. Head is

proportionate to body. Nose is straight. The horns

are strong, broader at base, pointed tip, grey in

colour, curving backward. Muzzle is black, hooves are

grey. Underbelly is also black. Beard is seen in few

animals of both sexes. These goats are slightly

shorter than Singharey goats but their face, horn and

tail are comparatively longer.

The average measurements of different body

traits are presented in table 1. The mean

estimates for height at withers, body length,

Chest/heart girth, paunch girth, face length,

horn length, ear length and tail length in adult

( >18 months) female goats were 50.06±0.85,

58.75±0.73, 70.65±0.73, 79.57±1.17, 17.11±0.20,

1 0 . 1 7 ± 0 . 5 3 , 1 2 . 7 0 ± 0 . 2 3 , 1 0 . 3 5 ± 0 . 2 4 c m ,

respectively whereas for males the average

measurements were 54.70±1.19, 61.80±1.39,

75.97±1.48, 82.30±1.76, 17.90±0.29, 15.070±.77,

13.50±0.36 cm. The average body weight for adult

females was 28.48±0.72 kg and males 34.87±1.56 kg.

The averages for the same biometric traits of adult

Singharey goats were 52.52±0.71, 60.29±0.66,

67.98±0.59, 74.52±1.25, 16.16±0.19, 8.84±0.33,

13.48±0.18 & 10.88±0.24 cm respectively in

females and 55.67±0.93, 61.48±0.86, 71.66±0.85,

76.47±1.16, 17.20±0.22, 14.58±0.57, 12.92±0.24 &

11.89±0.25 cm respectively in males. The body

weights were 27.33±0.65 kg in adult females and

31.03±0.92 in males ( Verma et al. 2015b). On

comparing the biometry of two populations Sikkim

Black goats were found to be heavier due to more

Figure 1. Sikkim Black goats exhibiting the different morphological features

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TRAITS Females Male

(n=63) (n=30)

Body Height 50.06±0.85 54.70±1.19

Body Length 58.75±0.73 61.80±1.39

Chest Girth 70.65±0.73 75.97±1.48

Paunch Girth 79.57±1.17 82.30±1.76

Face Length 17.11±0.20 17.90±0.29

Horn Length 10.17±0.53 15.070±.77

Ear Length 12.70±0.23 13.50±0.36

Tail Length 10.35±0.24 12.20±0.40

Body Weight 28.48±0.72 34.87±1.56

Table 1. Mean body measurement (cm) and body weights (kg) of adult Sikkim Black goats

average values of Chest girth, paunch girth, face

length and horn length.

Management: The �locks varying from 2 to more than

20 animals were observed in the �ield (�ig.2). These

goats like other goats of Sikkim are also maintained

under semi extensive production system where the

animals are left for pasture grazing in the morning

and brought back in the evening. Animal when stay

at home are kept on stall feeding. They are fed with

available local grass, leaves and sometimes

supplemented with crushed maize. At night, animals

are sheltered in temporary houses made of wooden

logs, bamboos and planks. The �loor of such houses

is made 3-4 ft above the ground. This type of housing

helps in maintaining cleanliness and proper

ventilation. Some houses have inbuilt mangers. The

metallic utensils are also used to serve the feed. A

special type of feeding manger is also made out of

wooden logs (�ig.3). Breeding is through natural

mating. Kidding season is March-April and October

–November. Since these goats are reared for meat

purpose, milk is not drawn but left for suckling of

kids. The male goats mature and becomes available

to serve at the age of 9-10 months but the males

reared for meat purpose are castrated at the age of 3

months. The age of maturity in female goats also

varies between 9-12 months. The average gestation

period is about �ive months. Twinning is very

common in these goats.

G e n e t i c D i v e r s i t y : T h e a l l e l i c n u m b e r,

heterozygosities, Shannon's information index, f

values were estimated for Sikkim Black goats and are

given in table 2. Observed number of alleles varied

from 2 to 9 with mean value 5.391±0.411 whereas

effective number varied from 1.145 to 6.400 with

mean 2.771±0.261. Observed number of alleles is

more than the expected number across the loci.

Observed heterozygosity (Ho) was less than the

Figure 2. A ock of Sikkim Black goats Figure 3. Housing and stall feeding

Volume 5, Number 1-2, 2015

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Locus

Allelic Number Hetrozygosity Shannon’s

Information Index

F estimate HWE

Na Ne Ho He

ChiSq Sign.

ETH225 3.000 1.686 0.333 0.407 0.699 0.181 21.000 ***

ILSTS044 6.000 2.374 0.200 0.579 1.248 0.654 59.710 ***

ILSTS008 5.000 1.896 0.500 0.473 0.933 -0.058 18.503 *

OarHH64 6.000 3.703 0.579 0.730 1.507 0.207 31.711 **

ILSTS059 4.000 2.014 0.250 0.503 0.937 0.503 17.108 **

ILSTS065 7.000 2.616 0.316 0.618 1.240 0.489 87.801 ***

OarJMP29 4.000 1.656 0.304 0.396 0.769 0.232 19.454 **

ILSTS033 7.000 2.160 0.438 0.537 1.173 0.185 27.878 ns

OarFCB48 4.000 3.522 0.556 0.716 1.320 0.224 6.407 ns

OMHC1 7.000 5.120 0.625 0.805 1.771 0.223 20.836 ns

ILSTS005 3.000 1.489 0.385 0.328 0.619 -0.171 0.737 ns

ILSTS019 3.000 2.502 0.222 0.600 0.998 0.630 13.835 **

ILSTS058 6.000 4.129 0.125 0.758 1.581 0.835 40.000 ***

ILSTS087 8.000 4.014 0.882 0.751 1.630 -0.175 50.711 **

ILSTS029 3.000 1.145 0.133 0.127 0.291 -0.053 0.077 ns

ILSTS049 6.000 2.916 0.364 0.657 1.397 0.447 35.750 **

ILSTS030 8.000 6.400 0.583 0.844 1.950 0.309 32.333 ns

ILSTS034 5.000 2.113 0.615 0.527 1.043 -0.169 6.181 ns

ILSTS022 4.000 1.866 0.421 0.464 0.902 0.093 8.252 ns

RM088 8.000 3.130 0.611 0.681 1.461 0.102 47.739 *

RM4 2.000 1.902 0.455 0.474 0.667 0.041 0.414 ns

ILSTS082 6.000 2.674 0.421 0.626 1.215 0.327 23.697 ns

OARE129 9.000 2.714 0.353 0.631 1.520 0.441 85.170 ***

Mean 5.391 2.771 0.420 0.575 1.168 0.239

SE 0.411 0.261 0.038 0.035 0.085 0.058

Table 2. Allele frequency and Genetic diversity of microsatellite loci in Sikkim Black goats

expected (He) at most of

the loci leaving ILSTS008,

ILSTS005, ILSTS0087,

ILSTS0029 and ILSTS034.

The values ranged from

0.125 to 0.882 with mean

0 . 4 2 0 ± 0 . 0 3 8 f o r

observed and from 0.127

t o 0 . 8 4 4 w i t h m e a n

0.575±0.035 for expected

h e t e r o z y g o s i t y .

Shannon's information

index value varied from

0.291 (ILSTS029) to 1.950

(ILSTS030) with mean

value 1.168±0.085. F

estimates varied from -

0.175 ( ILSTS087) to

0.835 (ILSTS058) with

mean value 0.239±0.058.

Some loci (ILSTS008,

ILSTS005, ILSTS0087,

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ILSTS0029 and ILSTS034) having higher observed

heterozygosities than the expected showed negative

F values. These loci indicated inbreeding depression

as a result of which there was increase in

heterozygosity. The population also exhibited HW

equilibrium w.r.t. ten loci where chi square values

were non-signi�icant, however, the reason for HW

disequilibrium at other loci is dif�icult to mark in the

small population of Sikkim Black which is also likely

to be subjected to in and out movement of animals

from the population.

Possibility of differentiation between Black Sikkim

and Singharey goats of Sikkim was also explored.

The multi-locus F values of breed differentiation for ST

different populations of Sikkim goats indicated that

only 3.6% of the total genetic variation was due to

unique allelic differences between the populations,

with the remaining 96.4% corresponding to

d ifferences among individuals within the

populations across the 23 markers (Verma et al.,

2015b). Dixit et al., (2012) observed moderate level

(16.5%) of genetic differentiation among Indian goat

breeds. Pairwise population Nei's genetic distance

and genetic identity values between Black Sikkim

and Singharey goat populations were 0.122 and

0.885 respectively. The assignment test based on

likelihood method with the leave one out procedure

assigned 57% of the Black Sikkim individuals to

Singharey population indicating the intermixing of

two populations. Principle Component Analysis

performed also did not indicate the distinctiveness of

these populations.

Bottleneck in�luences the distribution of genetic

variation within and among populations. In recently

bottlenecked populations, the majority of loci

exhibited an excess of heterozygotes, exceeding the

heterozygosity expected in a population at mutation

drift equilibrium. Signi�icant deviations from the

mutation-drift equilibrium are simply assessed by the

probability given by each test (Standardized differences

test or Wilcoxon test). A probability less than 0.05 would

allow accepting the hypothesis of genetic bottleneck

within the analyzed data. To estimate the excess of

such heterozygosity Standardized differences and

Wilcoxon sign rank tests were utilized. The actual

mutation model of evolution followed by our

microsatellites is not known, thus all the three

models; In�inite allele model (IAM), stepwise

mutation model (SMM) and two-phase model of

mutation (TPM) were applied. A normal 'L' shaped

distribution of mode–shift test (�ig. 4), non-

signi�icant heterozygote excess on the basis of

d i ff e re n t m o d e l s , a s re ve a l e d f ro m S i g n ,

Standardized differences and Wilcoxon sign rank

tests (table 3) suggested that there was no recent

bottleneck in the existing Sikkim Black goat

population.

The study concluded that there was genetic diversity

among the studied population but because of small

population size, and its intermixing with Singharey

goats, there is a reduction in genetic variability in

Sikkim Black goat population. Principal Component

analysis also showed the mixing of Sikkim Black and

Singharey goats in the same cluster. About 40% of

the loci were not in HW equilibrium and were

heterozygotic de�icit. Looking at the distinct

phenotype but sharing the breeding tract with

Singharey goats, there is a need to conserve and

propagate the population through appropriate

scienti�ic management.

Model used I.A.M. T.P.M. S.M.M.

Sign test (No. of loci with hetrozygosity excess) Exp 13.27 13.43 13.80

Obs 9 7* 5*

P- value 0.05588 0.00622 0.00021

Standardized differences test T2 value -0.838 -3.830* -7.909*

P- value 0.20104 0.00006 0.0000

Wilcoxon test (one tail for H excess) P- value 0.77740 0.99106 0.99985

Table 3. Population bottle neck analysis in Sikkim Black goat

Volume 5, Number 1-2, 2015

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ACKNOWLEDGMENTS

The authors are highly thankful to the Director

NBAGR for providing the facilities to carry out this

work. We sincerely thank the Secretary and the

Director, Department of Animal Husbandry,

Livestock, Fisheries and Veterinary Sciences, Govt. of

Sikkim. The Farmers / Goat keepers deserve our

special thanks for permitting us to take blood

samples from their animals.

REFERENCES

19th Livestock Census. 2012. Ministry of Agriculture,

Department of Animal Husbandry, Dairying

and Fisheries, Krishi Bhawan, N. Delhi.

Aggarwal RAK, Dixit SP, Verma NK, Mathew S, Kumar

D, Ahlawat SPS, Kumar S and Kumar Y. 2006.

Genetic diversity in Attapaddy breed of

Indian goat as analyzed with microsatellite

markers. Korean Journal of Genetics 28(3):

237-242.

Bostein, D, White R L, Skolnick M and Davis R W.

1980. Construction of genetic linkage maps

in man using restriction fragment length

polymorphism. American Journal of Human

Genetics 32: 314–331.

Cornuet J M and Luikart G. 1996. Description and

power analysis of two tests for detecting

recent population bottlenecks from allele

frequency data. Genetics 144: 2001–14.

Dixit S P, Verma N K, Aggarwal R A K, Vyas M K, Rana J

and Sharma A. 2012. Genetic diversity and

relationship among Indian goat breeds based

on microsatellite markers. Small Ruminant

Research 105: 38– 45.

Kimura M and Crow J W. 1964. The number of alleles

that can be maintained in a �inite population.

Genetics 49: 725–38.

Sambrook J, Fritsch E F, Maniatis T. 1989. Molecular

Cloning: A Laboratory Manual. Cold Spring

Harbor Laboratory Press, Cold Spring

Harbor, New York, USA

Verma N K, Dixit S P, Aggarwal R A K, Chander R,

Kumar S and Ahlawat S P S. 2007. Genetic

analysis of the Sirohi breed of Indian goat

(Capra hircus). Korean Journal of Genetics 29:

129–36.

Verma NK, Mishra P, Aggarwal RAK, Dixit SP, Dangi PS

and Dash SK 2015. Characterization,

performance, and genetic diversity among

goats of Odisha. Indian Journal of Animal

Sciences 85(2) : 168-171.

Verma N K, Aggarwal RAK, Sharma R, Dangi P S and

B h u t i a N T. 2 0 1 5 a . P h e n o t y p i c

characterization, biometry and management

of Singharey goat of Sikkim. Indian Journal of

Animal Sciences 85 (7): 810–812.

Verma N K, Aggarwal, Sharma R, Dangi P S Shivhare, P

and Bhutia N T. 2015b. Goat germplasm of

Sikkim state. A Monograph # 94/2015, ICAR­

NBAGR.

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thA study was undertaken on male (IWH) and female (IWI) line of White leghorn completing 29 generation of selection.

The average age at sexual maturity declined signi�icantly in both the strains with the estimates of –1.404 and –1.28 days in

IWH and IWI strains respectively on phenotypic scales. Corresponding estimates on genetic scales were –0.47 and –0.35 thdays per generation in IWH and IWI strains. The change in the average response per generation for egg weight at 28 and

th40 wk of age in both the selected strains were mostly non-signi�icant except for signi�icant negative genetic association of th th40 weeks egg production with egg weight at 40 week of age in IWI strain. Egg production (40 wk) improved signi�icantly

in the both the selected strains with the estimates of 0.880.15 and 0.690.15 eggs per generation in IWH and IWI strains on

genetic scale. Average responses per generation for various economic traits observed at 64th wks of age revealed that

body weight (BW-64) declined non-signi�icantly in both the selected strains except for positive but non-signi�icant thresponse for 64 wk body weight on phenotypic scale.

Genetic and phenotypic response to selection in various traits of IWH andIWI strains of White Leghorn under long term selection

M C Kataria, A K Mishra*, R K S Bais, S Kumar, Raj Narayan, S Johari and R Gopal AG & B Division, ICAR- Central Avian Research Institute, Izatnagar, Bareilly – 243122

ABSTRACT

Key words: Selection, genetic gains, White Leghorn

Present address: ICAR - National Bureau of Animal Genetic Resources, Karnal 132001

*Corresponding author: [email protected]

INTRODUCTION

The commercial layer breeders are using specialized

male and female lines for production of commercial

layers. At present most of the high yielding pure line

strains of layer stocks appear to be on the verge of

approaching plateau, due to exhaustion of additive

genetic variance and/ or other reasons (Bais et al.

2008). The IWH and IWI strains of White Leghorn are

undergone family index selection for increased egg

production to 64 weeks of age over more than 35

years. In any selection programme, the selection is

practiced either for a single or a combination of traits

and the individuals above a certain value for the

criteria of selection are selected as parents, thus

selection causes the variance among the parents to

be reduced. Therefore, the present study was carried

to evaluate phenotypic and genetic gains realized in

various economic traits in two strains of White

Leghorn selected for improved egg production.

MATERIALS AND METHODS

Two White Leghorn pure line populations viz. IWH &

IWI and along with control (IWC) maintained at

Experimental Layer Farm ICAR- Central Avian

Research Institute, Izatnagar, Bareilly (U.P.) since th

early seventies and completing 29 generation as

closed �lock constituted the genetic stock for the

present study. Having undergone family index

selection over 28 generation, the IWH (male) and IWI

(female) lines were hatched simultaneously along

with the control line (IWC).

All the selected and control lines were maintained

under standard and uniform management condition.

In general chicks were obtained in 3-6 hatches in

different generations. The chicks were identi�ied

individually and brooded on deep litter up to 8 weeks

of age. After separation of sexes at 8 weeks of age,

only 2 male chicks per dam in the selected lines and 1

male chick per dam in the control line and all the

female chicks were retained for further study. The

pullets were housed in 3 tier individual laying cages

at about 18 weeks of age.

The hatch corrected data were utilized for estimating

genetic parameters by full sib correlation method

using mixed model Least squares and maximum

likelihood (LSMLMW) computer programme

(Harvey 1990). The phenotypic responses per

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Traits Strain

IWH IWI

BW at 16thwk -24.45±23.012 -10.79±18.88

BW at 40thwk -6.11±1.826** 4.06±6.15

BW at 64thwk -5.81±19.58 8.26±20.48

ASM -1.404±0.16** -1.28±0.13**

EW at 28th wk -0.324±0.29 -0.16±0.28

EW at 40th wk 0.019±0.047 -0.03±0.04

EW at 64thwk -0.45±0.32 -0.15±0.48

EP up to 40th wk 1.452±0.14** 1.253±0.15**

EP up to 64thwk 1.55±0.37** 1.65±0.36**

Table 1. Phenotypic response in various production traits in

generation within line for economic traits were

estimated as the regression of generation means (Y)

on generation numbers (X). The realized genetic

gains per generation in both selected and correlated

traits were estimated by the regression of control

deviated generation means of selected lines on

generation numbers.

RESULTS AND DISCUSSION

Average response per generation for various

economic traits up to 64 wks of age were estimated

on genetic and phenotypic scales and presented in

table 1 and 2. The average response per generation thfor initial body weight (16 wk ) was found to be

negative and non signi�icant for both the selected

strains, both on genetic and phenotypic scales; the

estimates were –24.4523.01 g, -10.7918.88 g and

–4.2920.13 g in IWH, IWI and IWC strains th

respectively. For 40 wk body weight, the average

response per generation was negative and

signi�icant with the estimates of –4.051.61** g and

–6.111.82** g on genetic and phenotypic scales

respectively in IWH strain. The results agreed well

with the report of Bais et al. (2008). The negative

response may be attributing to negative genetic

association of 40 weeks body weight with egg

production for this line. In IWI strain the estimates

were positive but non-signi�icant with the estimates

of 6.126.15 g and 4.066.15 g on genetic and

phenotypic scales respectively.

The average age at sexual maturity declined

signi�icantly in both the strains with the estimates of

–1.4040.16** days and –1.280.13** days in IWH and

IWI strains respectively on phenotypic scales.

Corresponding estimates on genetic scales were

–0.470.16** days and –0.350.11 days per generation

in IWH and IWI strains. The egg production was the

criterian of selection hence, reduction in age of

sexual maturity might have contributed to the

principal trait i.e. egg production upto 64 weeks of

age. Similar �indings/arguments have also been

reported by Bais et al. (2008). Kumar and Singh

(2009) also reported reduction in age at sexual

maturity for broiler dam and sire lines. The reduction

in ASM is expected when the criterion of selection is

egg production at �ixed age. In such cases the

selection for increased number of eggs favors the

early maturity on account of their negative genetic

association (Bais et al. 2008).

The change in the average response generation for th th

egg weight at 28 and 40 wk of age in both the

selected strains (H & I) were mostly non-signi�icant

except for signi�icant negative genetic association of th th

EP (40 wk) with egg weight at 40 week of age in IWI

strain. At 64 weeks of age body weight (BW-64) and

egg weight (EW-64) declined non-signi�icantly in

both the selected strains except for positive but non-th

signi�icant response for 64 wk body weight on thphenotypic scale and for 64 wk egg weight on

** Signi�icant at P<0.01; BW= Body weight, ASM = age at sexual maturity,

EW= egg weight, EP= egg production.

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Traits Strain

IWH IWI IWC

BW at 16thwk -20.15±10.59 -6.49±11.60 -4.29±20.13

BW at 40thwk -4.05±1.61** 6.12±6.15 -2.06±1.48

BW at 64thwk -32.87±17.36 -18.60±16.90 26.87±14.38

ASM -0.47±0.16** -0.35±0.11** -0.93±0.15**

EW at 28th wk 0.14±0.22 0.297±0.17 -0.46±0.31

EW at 40th wk 0.06±0.04 -0.11±0.03** 0.076±0.04

EW at 64thwk -0.08±0.32 0.22±0.25 -0.37±0.36

EP up to 40th wk 0.88±0.15** 0.69±0.15** 0.56±0.17**

EP up to 64thwk 1.22±0.29** 1.32±0.68 0.33±0.38

Table 2. Genetic response in selected strains and time trend in control population for various production traits.

** Signi�icant at P<0.01; BW= Body weight, ASM = age at sexual maturity,

EW= egg weight, EP= egg production.

genetic scale in IWI strain. The negative genetic gains

in egg weight indicated a declining trend for egg

weight across the generation and agreed full with the

�indings of Pattanayak and Patro (1995) and Bais et

al. (2008). t h

Egg production (40 and 64 wk) improved

signi�icantly in the both the selected strains with the

estimates of 1.22 0.29** and 1.320.68** at 64 weeks

of age in IWH and IWI strains on genetic scale.

Corresponding estimates on phenotypic scales were

observed to be 1.55 0.37** and 1.650.36** in IWH

and IWI strains. In contrast to present study

Shrivastava et al. (1989) could not �ind any

signi�icant response in spite of improvement in the

selected trait. However, John et al. (2000), Chatterjee

and Mishra (2002) and Devi and Reddy (2004)

reported positive and signi�icant phenotypic

response in egg production up to 280 days of age.

Average response per generation for various th

economic traits up to 64 wk of age in the control

population revealed non-signi�icant changes in body th th th

weight at 16 and 40 wk of age and egg weight at 28 th th

and 40 weeks of age. However, for ASM and 40 wk

egg number, the changes were signi�icant which

might be due signi�icant changes due to overall

improved managemental conditions provided to the

control population along with the selected strains in

the preceding few generations and also natural

selection of birds of 64 wks of age. It is quite natural

that the birds reproduce next generation after 64

wks of age will good egg producers. It will be t himportant to mention here that for 64 wk

production traits, IWC showed non-signi�icant

changes in the preceding generations.

The genetic gains realized in both the strains were

indicative of successful application of selection

programme for improving egg production.

ACKNOWLEDGEMENT

The authors are highly grateful to the Director, ICAR-

Central Avian Research Institute Izatnagar for

providing necessary facilities and Dr R D Sharma for

their help for statistical analysis of data. The authors

are also thankful to Indian Council of Agricultural

Research New Delhi for providing funds.

REFERENCES

Bais R K S, Kataria M C, Johari D C, Sharma D, Hazary R

C and Nischal. 2008. Genetic gains from

reciprocal recurrent selection for part period

egg production in White Leghorn layers,

Indian Journal of Poultry Science, 43(2): 143 –

149.

Chatterjee R N and Mishra B S .2002. Realized

phenotypic response in the performance and

time trends of genetic parameters in a White

Leghorn population, Indian Journal of Poultry

Science, 37: 35-39.

Devi K S and Reddy P M. 2004. Phenotypic and

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genetic response in primary and various

correlated traits in White Leghorn layers,

Indian Journal of Poultry Science, 39: 54-56.

Harvey W R. 1990. User's guide. LSMLMW and

MIXMDL PC -2 version. Mixed model least-

squares and maximum likelihood computer

programme, Ohio, USA.

John C L, Jalaluddin A and Anitha P. 2000. Impact of

selection for part period egg production in

two strains of White Leghorn, Indian Journal

of Poultry Science, 35: 156 – 160.

Kumar S and Singh R P. 2009. Expected and realized

response in various traits of broiler dam and

sire lines, Indian Journal of Animal Sciences,

79: 1066 -1068.

Pattanayak G R and Patro B N .1995. Evaluation of a

selection experiment for egg number and egg

weight in White Leghorn chicken, Indian

Journal of Animal Sciences, 65: 1131 – 1138.

Srivastava P N, Khan A G, Poulose M V and O P Dutta .

1989. Selection for egg production.1. Short

term response to selection in four strains of

while leghorn, Indian J of Animal Sciences, 59:

840-845.

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Genomic region corresponding to exon 2 of DQB gene was ampli�ied from 79 Indian mithuns. Three primers were used

(two forward and one reverse) to carry out Polymorphism studies. Ampli�ied products of DQB genes were digested with

HinfI restriction enzymes, which revealed a total of 2 restriction patterns in DQB. Nearly all the mithun population was

found to be �ixed for AA restriction pattern. PCR-RFLP results revealed very low variability at Hinf I site in Bofr-DQB,

contrary to PCR-RFLP studies of DQB gene in other bovines. Very low genetic diversity was observed at Hinf I loci at exon 2

region of mithun DQB, indicating conserved recognition site of Hinf I. Our study indicated that Hinf I enzyme may not be

good enough for the typing of DQB alleles in mithun population, on other side tetracutters may a good choice for the

genotyping of Bofr-DQB.

Low variability at Hinf I locus of Major Histocompatibility Complex (MHC) –DQB gene in Indian Mithun (Bos frontalis)

1 2 3D S Gonge , S K Niranjan*, S K Mishra, R K Singh , S Kumar and R S Kataria

ICAR - National Bureau of Animal Genetic Resources, Karnal – 132001 (Haryana) India

ABSTRACT

Key words: Mithun; MHC; DQ genes; duplicated haplotype; PCR-RFLP

INTRODUCTION

Mithun (Bos frontalis), is a massive, semi-

domesticated and rare bovine species and

considered descendent from wild Indian gaur

(Simoons 1984). Through contributing in terms of

meat, leather and drafting power, it plays an

important role in the day-to-day socioeconomic,

cultural and religious life of the local tribal

population of North East region of the India (Arora,

1998). Presently, India possesses 0.29 million

Mithun distributed mainly in Arunachal Pradesh, t h

Nagaland, Mizoram and Manipur states (19

Livestock Census, 2012). In view of small and

scattered populations of mithun in the region, major

efforts are being done to increase the population by

the various government and non-government

agencies in this region. Census shows the recent

increase of the mithun population in region during th threcent time (18 Livestock Census 19 Livestock

Census, 2012). However, it is essential to assess the

genetic diversity of functional markers in mithun, as

it re�lects the �itness as well adaptation of the

population to the local environment.

Functional markers like Major Histocomaptability

Complex (MHC) are preferred over neutral markers

like microsatellite for assessing the genetic diversity

in rare wild species as these, being directly

associated with host's immune response. Evidence

s u g g e s t s t h a t p o p u l a t i o n s w i t h e x t r e m e

monomorphism shown by neutral markers may

persists suf�icient genetic variation at the MHC

(Aguilar et al, 2004). Apart from critical role in

immune response, the genetic variations at MHC loci

are thought to have a signi�icant impact on

population �itness and regarded as being exploited

for increasing the diversity under conservation

programme for some of the rare wild animal species

(Yasukochi et al. 2012). Generally, MHC region is an

organized cluster of highly polymorphic genes

related with immunity. MHC class II genes,

speci�ically DRB3, DQA and DQB are extremely

polymorphic in ruminants Andersson and Rask,

1988, Sigurdardottir et al 1992, Marello et al 1995,

Ballingall et al., 1997). However, no such study has

been conducted to assess the variability at MHC loci

in mithun species. In view of small and scattered

populations of Mithun in the region, the genetic

diversity of these populations has been prime

1 2Present Address : Research Scholar, DCB, NDRI, Karnal, India; NRC on Mithun, Jharnapani, 3Medziphema India; Division of Animal Genetics, IVRI, Izatnagar, India

*Corresponding author: [email protected]

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S.N. Patterns Animals Frequency (%)

1 AA 76 96.20

2 AB 3 3.80

Table 1. Hinf I restriction patterns of Bofr-DQB

importance to assess the �itness for their better

survival and adaptation to the local environment.

Therefore, we conducted a study to identify genetic

variability at MHC-DQB loci in Mithun using PCR-

RFLP.

MATERIAL AND METHODS

Seventy nine mithun blood samples were collected

from different �ield areas of Nagaland and Arunachal

Pradesh of India. Genomic DNA was isolated by by

phenol-chloroform extraction method by standard

protocol (Sambrook and Russel, 2001) The purity of

t h e g e n o m i c D N A w a s a s s e s s e d b y

spectrophotometry the ratio of optical densities

value at 260 and 280 nm was used as a criteria for

purity. To amplify genomic sequence of DQB

encompassing exon 2, a set of three primers were

used referred by Traul et al . , (2005). For

ampli�ication of Bofr-DQB, two forward primers

(B1G-F-5'-TCCCCCGCAGAGGATTTCGTG-3' and

B2G-F -5'-CTCCCCGCAGAGGATTTCGTG-3') with

r e v e r s e p r i m e r B G - R - 5 ' -

CGCACTCACCTCGCCGCTGC-3). were multiplexed .

The optimized concentrations for 20 µl volume of

reaction mixture were 1.5 mM of MgCl , 2mM of 2

dNTPs and 10 pmol of primers each, 100 ng of

genomic DNA as template, 10x PCR assay buffer and

3 units of Taq DNA polymerase. Ampli�ication

conditions were: initial denaturation at 95 °C for 3

minutes, 32 cycles of denaturation for DQA and 34 cycles for DQB at 94 °C for 30 seconds, annealing 65

°C f for 30 seconds and extension at 72 °C for 1

minute for DQA and 40 seconds for DQB and �inal

extension at 72 °C for 10 minutes. Ampli�ied PCR

products were digested with HinfI restriction

enzyme for RFLP analysis. Digested products were

analyzed by gel electrophoresis by using 2.5% high

resolution agarose gel in gel electrophoresis at 80V

for 2 hour. The frequency of different patterns was

estimated by using standard method.

RESULTS AND DISCUSSION

289 long nucleotide region encompassing respective

highly variable regions (exon 2) nucleotide

sequences of DQB genes, respectively were ampli�ied

in 79 Mithun. Ampli�ied products of DQB genes were

digested with HinfI restriction enzymes, which

revealed a total of 2 restriction patterns in DQB

(Figure 1). The frequencies of different patterns with

fragment size are given in table 1. Nearly all the

mithun population was found to be �ixed (96.2%) for

AA restriction pattern. PCR-RFLP results revealed

very low variability at Hinf I site in Bofr-DQB,

contrary to PCR-RFLP studies of DQB gene in other

bovines (Marello et al, 1995, Niranjan et al, 2010a &

b). Although, more number of restriction patterns

has been identi�ied in cattle and buffalo DQB,

however by using other enzymes. Niranjan and

coworkers (2010b) also adopted the Hae III enzyme

for typing of DQA alleles in buffaloes and revealed six

patterns.

Our results indicated that the recognition site

(G/ANTC) of Hinf I in DQB alleles may be conserved.

Further, Hinf I enzyme was tried in this study,

however, never been reported for typing of DQB

alleles in any species, to the best of our knowledge, by

any worker. Our study indicated that Hinf I enzyme

may not be good enough for the typing of DQB alleles

in mithun population, on other side tetracutters like

Hae III, Rsa I may a good choice for the genotyping of

Bofr-DQB.

In conclusion, very low genetic diversity was

observed at Hinf I loci at exon 2 region of mithun

DQB, indicating conserved recognition site of Hinf I.

Figure 1: Electrophoretic mobility of RE fragments obtained by digestion ofBofr-DQB exon-2 region with HinfI ( in 2.5% agarose gel)Lane 1-15: Different restriction patternsLane M: 100 bp DNA ladder

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Our study indicated that Hinf I enzyme may not be

good enough for the typing of DQB alleles in mithun

population, on other side tetracutters may a good

choice for the genotyping of Bofr-DQB.

ACKNOWLEDGMENT

The authors wish to acknowledge the Director

of NBAGR and NDRI, Karnal, for use of

facilities. The �inancial assistance provided by

Department of Animal Genetics and Breeding

are also duly acknowledged.

REFERENCES

Aguilar A, Roemer G, Debenham S, Binns M,

Garcelon D, and Wayne RK. 2004. High MHC

diversity maintained by balancing selection

in an otherwise genetically monomorphic

mammal Evolution. Proc Natl Acad Sci U S A.

101(10): 3490–3494.

Andersson, L. and Rask, L. 1988. Characterization

of the MHC class II region in cattle: The

number of DQ genes varies between

haplotypes. Immunogenetics 27, 110-120.

Arora CL. 1998 Less used animal: Yak and

Mithun- an over view. Indian Journal of

Animal Science. 68: 735-742.

Ballingall, K.T., Luyai, A. and McKeever, D.J. 1997.

Analysis of genetic diversity at the DQA loci

in African cattle: evidence for a BoLA DQA3

locus? Immunogenetics 46, 237-247

Marello, K.L., Gallagher, A., McKeever, D.J., Spooner,

R.L. and Russell, G.C. 1995. Expression of

multiple DQB genes in Bos indicus cattle.

Animal Genetics. 26: 345-49.

Niranjan, S. K., Deb S. M., Sharma A., Kumar S., Mitra

A., Sakaram D. Naskar S. and Sharma S. R.

2010a. Allelic diversity at MHC class II DQ

loci in buffalo (Bubalus bubalis): Evidence

for duplication. Veterinary Immunology and

Immunopathology 138: 206-212

Niranjan, S.K., Sharma, A. Deb, S.M., Naskar, S., and

Sakaram, D. 2010b. PCR-RFLP based

identi�ication of duplicated DQA loci in

riverine buffalo. Journal of Livestock

Biodiversity, 2: 64-66.

Sambrook J. and Russel, D.W. 2001. Molecular

coloning : A laboratory manual 3rd edition.

Cold Spring Harbor Laboratory Press, New

York.

Sigurdardottir, S., Borsch, C., Gustafsson, K.,

Andersson, L., 1992. Gene duplications and

sequence polymorphism of bovine class II

DQB Genes. Immunogenetics 35 (3),

205–213.

Traul DL, Bhushan B, Eldridge JA, Crawford TB, Li

H, Davies CJ. 2005. Characterization of Bison

bison major histocompatibility complex

class IIa haplotypes. Immunogenetics,

57(11):845-54.

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Effect of different diets of full fat soybean (�lake) on the meat compositionof broilers

DS Rasane and SS Kamble*

Mahatma Phule Krishi Vidyapeeth, Rahuri-413 722 (India).

In the three feeding trials of broilers the meat composition at 6 weeks and 8 weeks age was studied. The meat

composition at 6 weeks age indicated that the water content in Trial-I, II and III irrespective feed treatment

ranged from 73.23 to 74.70 per cent. The corresponding values at 8 weeks age ranged from 71.70 to 72.75 per

cent.There was no signi�icant difference in all the treatments as well as all the trials. However, water content in

the meat of birds at advanced age (8 weeks) was comparatively less than 6 weeks age.The protein content of

meat at 6 and 8 weeks age ranged from 18.06 to 18.25 per cent. The protein percentage of meat was neigher

affected by treatment diets nor by different trials. The fat content in meat at 6 weeks age ranged from 6.03 to

7.33 per cent in all treatments and all the three trials. At 8 weeks age fat content in meat was ranged from 7.83

to 8.90 per cent. The fat content of meat was higher in T followed by T , T and T in all the trials. The fat 3 2 1 0

content of meat at 8 weeks was signi�icantly higher than 6 weeks meat in all the treatment diets of all the trials.

The ash content in the meat at 6 weeks age amongst the three trials did not show much differences and

remained almost similar. Similar trend was observed 8 weeks age however the results indicated that ash

content in the meat higher at increasing age. Amongst the different treatment diets �ish meal containing diet

(T ) showed higher ash percentage. The ash content in the meat was in decreasing order with increase in FFSB 0

level in the diet. In T containing diet meat ash content was signi�icantly lower than T , T and T .3 0 1 2

INTRODUCTION

For getting tender meat broilers are marketed at �ive

to six weeks age. However in broiler market, rates are

�luctuating very much and many times broiler

owners have to bear the losses. To avoid such losses

the birds are retained even up to eight weeks of age.

At eight weeks of age the tenderness is not affected

but what sort of chemical changes takes place at

different age of marketing of birds is to be studied.

Therefore in the present experiment chemical

composition of broiler meat at six and eight weeks

age under different diets have been studied.

MATERIALS AND METHODS

In this investigation three experimental trials were

conducted i.e. in the month of September-October,

November-December (2000) and March-April, 2001.

During these trials different diets were given to the

birds, viz., T (Control) received 5 per cent �ish meal, 0

T , T and T received the diet containing 5, 10 and 15 1 2 3

per cent full fat soybean �lake (FFSB), respectively.

After attaining 6 weeks age and 8 weeks age,

5 birds from each treatment were slaughtered for

studying the meat composition. The birds were

fasted for 12 hours for complete emptying of crop

and intestine. The birds were weighed and

sacri�iced. The birds were slaughtered by modi�ied

Koshers' method (Panda and Mohapatra, 1998). In

this method the jugalar vein was severed just below

the ear taking care not to cut the wind pipe and

oesophagus. This method is widely used since the

birds could be better bled. The meat analysed by

AOAC (1990) method for determination of water,

protein, fat and ash content.

RESULTS AND DISCUSSIONS

Water Content in meat :­ Raw meat composition

(Table 1) indicated that the moisture percentage at 6

weeks age was in the range of 73.34 to 74.70, 74.15 to

74.66 and 73.23 to 73.77 in Trial-I, Trial-II and Trial-

III, respectively. Water content of meat in T was 0

signi�icantly higher than T , T and T indicated that 1 2 3

ABSTRACT

Key words : Meat composition, broiler, soybean

Corresponding author : [email protected]

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there was signi�icant difference in all the

treatments as well as in the three trials. However,

in the Trial-III water content was less as compared

to the �irst two trials, which might be due to hot

climatic conditions prevailing during that trial.

Water content in meat at 8 weeks age (Table 2)

ranged from 72.43 to 72.86, 72.50 to 72.95 and

71.70 to 71.95 in Trial-I, Trial-II and Trial-III,

respectively. The water content in meat of T was 0

signi�icantly higher than T , T and T . There was 1 2 3

signi�icant different in all the treatments as well as

in the three trials. At eight weeks also the water

content in meat of third trial was comparatively

less than the �irst two trials. Sahoo and Shingari

(1992) reported the moisture percentage of

broiler meat ranging from 70.5 to 71.9. They

further stated that in summer and spring season

m o i s t u r e p e r c e n t a g e i n t h e m e a t w a s

comparatively less than winter season.

Protein Content in meat : The protein content in the

meat of birds in Trial-I, Trial-II and Trial-III at 6

weeks age was almost similar which ranged

between 18.06 and 18.25 per cent. The protein

percentage of meat was thus not affected by

various treatment diets.

Similarly at the age of 8th week (Table 2) the

protein content of meat in all three trials was in the

range of 18.12 to 18.25 per cent. The protein

percentage of meat at 6 weeks and 8 weeks age

remained almost constant. There was no

signi�icant difference in all the treatments at 6

weeks and 8 weeks age. Bonami et al. (1970)

revealed that the different levels of �ish meal in the

diet did not give any difference in the meat

composition. Similarly Sahoo and Shingari (1992)

reported that the protein per cent of meat did not

change at 6 and 8 weeks age.

Fat Content in meat : The fat content in the meat

from 6 weeks broiler ranged from 6.33 to 7.30, 6.03

to 6.52 and 6.90 to 7.33 per cent in Trial-I, Trial=II

Volume 5, Number 1-2, 2015

Table 1. Average chemical composition of meat of broilers under different treatment diets and trials at 6 weeks age

Treatment Parameters (per cent)

Water Protein Fat Ash

Trial - I

T0

T1

T2

T3

Cal. 't' value

74.70

73.83

73.67

73.34

5.293

18.06

18.06

18.12

18.12

1.845

6.33

6.67

6.95

7.30

3.141

0.84

0.82

0.82

0.77

2.443

Trial - II

T0

T1

T2

T3

Cal. 't' value

74.66

74.30

74.27

74.15

5.435

18.00

18.12

18.12

18.15

2.153

6.03

6.37

6.45

6.52

2.572

0.85

0.83

0.83

0.80

2.315

Trial - III

T0

T1

T2

T3

Cal. 't' value

73.77

73.70

73.58

73.23

6.145

18.12

18.18

18.18

18.25

2.233

6.90

6.97

6.97

7.33

3.015

0.83

0.83

0.82

0.76

2.714

Each value is an average of 5 observations

15

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and Trial-III, respectively. The fat per cent was

signi�icantly higher in T (7.34%) followed by T 3 2

(6.95%), T (6.67%) and the lowest was in T (6.33%) 1 0

in the �irst trial.

In the Trial-II, similar trend was observed i.e. T 3

(6.52%) containing signi�icantly higher fat followed

by T (6.45%), T (6.37%) and the lowest was in the T 2 1 0

(6.03%).

The fat content of meat from Trial-III also indicated

the similar pattern. The T group contained 3

signi�icantly higher fat (7.33%) in the meat followed

by T (6.97%), T (6.97%) and T (6.90%) groups 2 1 0

respectively. The higher fat content in T and T may 3 2

be due to more synergic effect of poly-saturated acid

resulting in higher level of full fat soybean diet.

Barua et al. (1991) reported that the increase in

ambient temperature increased carcass fat content.

They observed non-signi�icant differences in the

carcass

fat content of broilers when reared at 27°C and 29°C.

However, when temperature was higher than 30°C

fat content increased in the carcass.

In trial-III fat per cent of meat was comparatively

higher because during hot part of the year water

losses from the body of bird might be more leading to

comparatively less water content of meat and higher

fat content. The fat content in meat of 8 weeks

broilers in Trial-I, II and III ranged from 8.00 to 8.23,

7.83 to 8.17 and 8.65 to 8.90, respectively. The fat

content in meat was higher in T followed by T , T 3 2 1

and T in all the trial. It was observed that the fat 0

content in 8 weeks meat was higher than 6 weeks

meat. Barua et al. (1991) revealed that the fat

content in carcass increased with body weight and

age, the percentage of water, protein and ash

decreased with increased fat content. According to

Singh and Panda (1992) fat content in carcass was

the most variable component and any increase in the

Volume 5, Number 1-2, 2015

Table 2 : Average chemical composition of meat of broilers under different treatment diets and trials at 8 weeks age

Treatment Parameters (per cent)

Water Protein Fat Ash

Trial - I

T0

T1

T2

T3

Cal. 't' value

72.86

72.75

72.55

72.43

5.447

18.12

18.12

18.18

18.18

1.935

8.07

8.00

8.15

8.23

2.524

0.88

0.87

0.82

0.80

3.013

Trial - II

T0

T1

T2

T3

Cal. 't' value

72.95

72.77

72.63

72.50

5.177

18.12

18.15

18.15

18.18

1.623

7.83

7.95

8.03

8.17

2.995

0.89

0.89

0.87

0.85

2.146

Trial - III

T0

T1

T2

T3

Cal. 't' value

71.95

71.91

71.82

71.70

4.166

18.18

18.15

18.25

18.25

1.983

8.65

8.73

8.87

8.90

3.115

0.87

0.86

0.86

0.84

2.238

Each value is an average of 5 observations

16

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fat was accompanied by a parallel decrease in water

content and vice-versa.

Ash content in meat : The chemical analysis of meat at

6 weeks age showed that the total ash content in the

meat was the highest in T (0.84%) followed by T 0 1

and T (0.82%) and the lowest was in T (0.77%) in 2 3

Trial-I. Similar trend was observed in Trial-II and

Trial-III. Student 't' test indicated that in all the trials

T , T and T were at par, only T was signi�icantly 0 1 2 3

lower in ash content than the rest of treatments.

The results of 8 weeks in Trial-I indicated that ash

content in meat was signi�icantly higher in T 0

(0.88%) and T (0.87%) than T (0.82%) and T 1 2 3

(0.80%) . Similar trend was observed in Trial-II and

Trial-III.

The ash content in the meat at 6 weeks age amongst

the three trials did not show much differences and

remained almost similar. Although the similar trend

was observed at 8 weeks, the results indicated that

ash content in the meat was higher at this age.

Further, it was also observed that amongst the

different treatment diets studied the �ish meal

containing diet (T ) showed higher ash percentage. 0

The ash content in the meat was in decreasing order

with increase in FFSB level in the diet. There was not

much difference in the ash content of meat in T , T 0 1

and T . Whereas in T diet ash content in 2 3

the meat was signi�icantly lower than the T , T and 0 1

T . It may be due to higher fat content in the diet 2

containing 15 per cent full fat soybean.

The higher level of un-extracted soybean diet intake

reduced the calcium and phosphorus retention

(Leeson et al. 1988). Similarly Mahapatra (1992)

observed that the high fat intake in the diet interfered

with the absorption of calcium and vitamin-D3.

REFERENCES

AOAC. 1990. Of�icial methods of analysis of the

Association of of�icial Analytical chemists. th15 edition, Association of of�icial Analytical

chemist INC Suite, Arlington, Verginia,

U.S.A.1 : 69-84, 949

Barua A, Howlider MAR and Rahman MA. 1991.

Factors affecting abdominal fat and

procedures for its reduction in broilers.

Poultry Guide 28 (8) : 49-51.

Bonami A, Bianchi M, and Benatti, G. 1970. In�luence

of rations with different contents of animal

protein on the health and productivity of

meat chicken. Nutr. Abstr. Rev. 41 (4) : 1391.

Leeson S, Atteh JO and Summers JD. 1988. Effects of

increasing dietary levels of commercially

heated soybeans on performance, nutrient

retention and carcass quality of broiler

chicken. Nutr. Abstr. Rev. 58 (5) : 314.

Mahapatra N. 1992. Importance of fats and fatty

acids in poultry with special emphasis on

health problems. Indian Poult. Rev. 23 (1) :

33-37.

Panda B and Mohapatra SC. 1998. Poultry

production. Publication and information

division, ICAR, Krishi Anusandhan Bhavan,

N.Delhi : 119-122.

Sahoo G and Shingari BK. 1992. Effect of �loor space

on meat quality in commercial broilers.

Poultry Guide 29 (11) : 39-43.ndSingh KS and Panda B. 1992. Poultry nutrition. 2

ed. Kalyani Publ. Co. Pvt. Ltd., Ludhiana : 33.

Volume 5, Number 1-2, 2015

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Tissue related in-silico mining of single nucleotide polymorphisms (SNPS) fromexpressed sequence tags (ESTS) in livestock species

Neeraj Kumar Dhaliwal, Aruna Pandey, Birham Prakash and Avnish Kumar Bhatia*ICAR - National Bureau of Animal Genetic Resources, Karnal – 132001 (Haryana) India

INTRODUCTION

Expressed Sequence Tags (ESTs) are partial

sequences of complementary DNA (cDNA) clones

measuring several hundred nucleotides [Baxevanis

and Ouellette, 2001]. There have been voluminous

increases in EST data generation and submission,

especially for livestock species, to the primary

databases such as NCBI, DDBJ and EMBL. Single

nucleotide polymorphisms (SNPs) are the simplest

type of genomic variation. Over the past decade,

SNPs have been the genetic markers of choice due to

their high density, stability and the highly automated

techniques for their detection [Kerstens et al., 2009].

Thousands of potentially informative SNP markers

can be identi�ied for development of high density

SNP maps [Zimdahl et al., 2004], which are an

essential resource to identify genes responsible for

variation of complex traits or Quantitative Traits Loci

(QTL) [Andersson, 2001; Andersson and Georges,

2004]. SNP analysis provides an important tool in

applications such as genetic linkage mapping, �ine

mapping of candidate regions and to determine

haplotypes associated with traits of interest [Panitz

et al., 2007]. With availability of genome sequence

assembly of a number of livestock species like cow,

sheep, chicken, pig and horse, mining of sequence

data for identi�ication of SNPs is a major task for

researchers. Huge amount of EST data for livestock

species- pig and cattle on different tissues like skin,

mammary gland, spleen, liver, intestine etc. are

available in public databases. ESTs data allow

discovery of SNPs in the transcribed regions [Marth,

2003].

There are few studies showing importance of tissue-

Related SNPs, particularly in species of economic

importance such as livestock species. In a study of

Tissue Speci�ic Temporal (TST) exome capture,

presence of tissue (muscle) speci�ic genes and SNPs

in Bubalus bubalis has been revealed [Jakhesara et al.,

2012]. Recent Genome Wide Association Studies

(GWAS) in humans have revealed that the genetic

variants may be operating in tissue dependent

manner. Subsets of genetic polymorphisms show a

statistical association with transcript expression

levels, and have therefore been called as expression

quantitative trait loci (eQTLs) [Nicolae et al., 2010].

In this study we have used a bioinformatics pipeline

for mining of in­silico tissue-related SNPc from EST

data in pig and cattle. Discovered SNPs have been

validated by revealing their availability in dbSNP

database. A database of tissue wise SNPs for livestock

ABSTRACT

Tissue speci�ic Single nucleotide polymorphisms (SNPs) hold signi�icance as potential expressed

Quantitative Trait Loci (eQTL). Although there have been numerous studies for mining SNPs in livestock

species, there is little focus on discovery of tissue-speci�ic SNPs. We performed tissue related in­silico SNP

mining from Expressed Sequence Tags (ESTs) in two livestock species - pig and cattle. EST data for tissues

such as skin, liver, spleen, intestine and mammary gland for the two species were downloaded from NCBI

website. ESTs were pre-processed using the online tool EGassembler and assembled into contigs using CAP3

program. SNPs were predicted from contigs using QualitySNP tool. Contigs were searched in the genome

assembly of a species using Blat tool in UCSC genome browser. Perl scripts were written to �ind genomic

position of SNPs from the alignment of contigs with the genomic segments, and to �ind availability of

predicted SNPs in the dbSNP database. A database of tissue related SNPs was developed.

Keywords: EST, SNP, tissue-speci�ic, livestock, eQTL

*Corresponding author: [email protected]

Volume 5, Number 1-2, 2015

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species have also been developed with additional

information on genes.

METHODS

EST data processing : EST data for different tissues of

pig and cattle were downloaded from dbEST

d a t a b a s e a v a i l a b l e a t N C B I

(www.ncbi.nlm.nih.gov/nucest). ESTs needs

processing to remove low quality DNA sequences,

contaminating sequences such as vector sequences

and repetitive sequences [Chou and Holmes, 2001].

The preprocessing was performed using online tool

EGassembler [Masoudi-Nejad et al., 2006], which

performs sequence cleaning, repeats masking and

vector cleaning as a single operation. Repbase

repeats library for the respective species was

selected as repeats library to remove repetitive

sequences and NCBI core vector library was chosen

for vector masking process. Processed ESTs were

free from low quality sequences, poly A/ poly T tail,

repetitive sequences and the vector sequences.

ESTs were assembled in contigs using the cluster

assembly program CAP3 [Huang and Madan, 1999]

using default parameters, which performs clustering

or assembly of the sequences into contigs by

pairwise sequence similarity searches between

sequences.

SNP identi�ication : Contigs were analyzed for SNPs

using SNP prediction tool QualitySNP [Tang et al.,

2006] with default parameters. This tool takes the

contigs.ace �ile generated by CAP3 tool as input and

predicts SNPs on contigs. SNPs predicted by the tool

are differentiated into three categories, viz., potential

SNPs, High Quality SNPs and Reliable SNPs. It

provides position of SNPs on contigs, number of SNPs

on each contig, major and minor alleles and d-value

denoting the standard deviation of normalized

number of SNPs per haplotype, which identify

clusters that probably contains paralogs.

SNPs position on chromosome and availability in

dbSNP Database : Contigs with potential SNPs were

searched in the genome assembly of a species in

UCSC Genome Browser using BLAT tool (http://

genome.ucsc .edu/cgi-bin/hgBlat? command=start).

This tool provides alignment of the contig with

particular chromosome segment of a species.

SNPs data of both the species were downloaded from

E n s e m b l G e n o m e B r o w s e r ( h t t p : / / a s i a .

ensembl.org/biomart/martview/), which included

S N P n a m e , S N P t y p e , c h ro m o s o m e n a m e ,

chromosome position, chromosome strand, SNP

alleles, Ensembl gene id, gene name, and gene start

and gene end positions. SNP data were retrieved

separately for each chromosome for these two

species for ease of data handling on a computer.

Perl script was written to �ind position of SNPs in the

best alignment of contigs and genomic sequences as

obtained using the BLAT tool. These SNPs were

searched for their presence in the dbSNP database

a v a i l a b l e i n t h e E n s e m b l B i o m a r t

(http://asia.ensembl.org/biomart/martview/). The

perl script is available for download within online

database described in the section 3.

Database development : A database on Tissue-wise

SNPs mined from ESTs was developed using MySQL

and PHP to provide user-friendly interface on tissue

wise SNPs and their availability in dbSNP database.

SNPs data in text �iles was inserted into the database

using a perl script. Information on chromosomes and

genes were also inserted in the database.

RESULTS

Table-1 displays information of ESTs and SNPs

discovered in pig and cattle. There were 50410 ESTs

in dbEST database for skin tissue of pig. Assembly of

these ESTs provided 6476 contigs and a total of 3444

SNPs were identi�ied out of which 1550 were high

quality SNPs and 834 were reliable SNPs. Only 421

out of 3444 detected SNPs were found in dbSNP

database.

The database developed on tissue-wise SNPs

provides a user-friendly web interface for data query

and visualization on search terms such as species

name, tissue name, chromosome name and gene

name. Output �ield settings include dbSNP name,

gene name, chromosome name, contig name and

sequence. SNPs are retrived with information on

high quality SNPs, reliable SNPs, Blat strand, dbSNP

strand, dbSNP id, dbSNP allele, contig allele, contig

name and sequence. The database also provides

genomic information such as Ensembl gene id,

Ensembl gene name, gene start position, gene end

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position, chromosome name and position of SNP on

chromosome. Information on tissue-wise SNPs is

linked to other databases such as Ensembl genome

browser and dbSNP database. The database is

accessible through a link 'Database' available at the

website http://www.nabgr.res.in/.

DISCUSSION

Signi�icance of tissue speci�ic SNPs, genes and eQTLs

has been highlighted recently in humans [Dimas et

al., 2009; Nica et al., 2011; Hernandez et al., 2012].

Tissue speci�ic SNPs have also been studied in

Bubalis bubalus [Jakhesara et al, 2012]. In these

studies, effects of genetic variants have been

reported in which 69 to 80% of the regulatory

variants are operating in cell-speci�ic manner. Also

eQTLs have been identi�ied, which may be unique or

shared among cell types or tissues. Many tissues and

cell types have speci�ic gene expression patterns and

so it is not clear how frequently eQTLs found in one

tissue type will be replicated in others. Therefore,

tissue speci�ic studies using SNPs to detect eQTLs

have been taken up. A unique set of tissue Related

eQTLs have been identi�ied in blood and brain tissues

in humans [Nica et al., 2011]. Nicolae et al., 2010

showed that SNPs associated with complex traits are

more likely to be eQTLs comparted to minor-allele-

frequency matched SNPs from GWAS. In view of

these studies, tissue speci�ic SNP mining should be of

considerable value in the livestock species.

We have performed tissue-related in­silico SNP

mining from EST data in two agriculturally

important livestock species - pig and cattle. These

SNPs were mined from EST data retrieved for a tissue

and therefore the SNPs discovered should be related

to the tissue. These SNPs were then located on the

genome assembly of the respective species and

validated by searching in the dbSNP database.

The present study reports a bioinformatics pipeline

for in­silico tissue-related SNP mining from EST data

in pig and cattle, locating these SNPs on the genome

assembly of the respective species, and searching

their availability in dbSNP database using perl script.

A number of potential SNPs were discovered in the

two investigated livestock species-pig and cattle

using the approach. A database of tissue-Related

SNPs has also been developed for use by researchers.

ACKNOWLEDGMENTS

Authors thankfully acknowledge funding by Indian

Council of Agricultural Research through National

Agricultural Innovation Project.

REFERENCES

Andersson L. 2001. Genetic dissection of phenotypic

diversity in farm animals.

Volume 5, Number 1-2, 2015

Table 1. Tissue related SNPs mined from ESTs in pig and cattle species

Livestock

species

Tissue ESTs Contigs Contigs

with

SNPs

SNPs High

Quality

SNP

ReliableSNP

Matches

in dbSNP database

Pig Skin 6476 698 3444 1550 834 421

Spleen 7575 761 5032 2389 1463 595

Mammary

Gland

1545 146 1687 1027 311 74

Liver 17941 2761 17082 8466 4499 2246

Cattle

Mammary

gland

8189 1158 10150 6031 2468 43

Intestine 394 32 192 75 55 0

Spleen 4890 808 3690 979 754 15

Liver

50410

73312

23061

129323

106150

3010

25781

178249 19664 4310 31023 16361 7141 157

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Nature Reviews Genetics 2:130-38.

Andersson L and Georges M. 2004. Domestic animal

genomics: Deciphering the genetics of complex

traits. Nature Reviews Genetics 5: 202-12.

B a x e v a n i s A D a n d O u e l l e t t e B F F. 2 0 0 1 .

Bioinformatics: A Practical Guide to Analysis of

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Chou HH and Holmes MH. 2001. DNA sequence

q u a l i t y t r i m m i n g a n d ve c to r re m ova l .

Bioinformatics 17(12): 1093-1104.

Dimas AS, Deutsch S, Stranger BE, Montgomery SB,

Borel C, Cohen HA, Ingle C, Beazley C, Arcelus MG,

Sekowska M, Gagnebin M, Nisbett J, Deloukas P,

Dermitzakis ET and Antonarakis SE. 2009.

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expression in a cell type dependent manner.

Science 325 (5945): 1246-50.

Hernandez DG, Nalls MA, Moore M, Chong S, Dillman

A, Trabzuni D, Gibbs JR, Ryten M, Arepalli S, Weale

ME, Zonderman AB, Troncoso J, O'Brien R, Walker R, Smith C, Bandinelli S, Traynor BJ,Hardy

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Jakhesara SJ, Ahir VB, Padiya KB, Koringa PG, Rank

DN, and Joshi CG. 2012. Tissue-speci�ic temporal

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and SNPs in Indian buffalo Bubalus bubalis.

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Kerstens HD, Kollers S, Kommadath A, Rosario MD,

Dibbits B, Kinders SM, Crooijmans RP and

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BMC Genomics 10: 4.

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Nica AC, Parts L, Glass D, Nisbet J, Barrett A, Sekowska

M, Travers M, Potter S, Grundberg E, Small K,

Hedman AK, Bataille V, Bell JT, Surdulescu G,

Dimas AS, Ingle C, Nestle FO, Meglio PD, Min JL,

Wilk J, Hammond CJ, Hassanali N, Yang TP,

Montgomery SB, O'Rahilly S, Lindgren CM,

Zondervan KT,Soranzo N, Barroso I, Durbin R,

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ET and Spector TD. 2011. The Architecture of

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Human Tissues: The MuTHER Study. PLoS

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et al. 2010. Trait-associated SNPs are more likely

to be eQTLs: annotation to enhance discovery

from GWAS. PLoS Genetics 6(4): e1000888.

Panitz F, Stengaard H, Hornshoj H, Gorodkin J,

Hedegaard J, Cirera S, Thomsen B, Madsen LB,

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Volume 5, Number 1-2, 2015

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Production and reproduction performance of Red Sindhi cow

R. P. Jadhav and S. S. Kamble*Department of Animal Husbandry and Dairy Science,

Mahatma Phule Krishi Vidyapeeth, Rahuri- 413 722 (India)

INTRODUCTION

Red Sindhi cow, also known as Sindhi Cow, Red

Karachi Cow is one of the most popular of all Zebu

dairy breeds. The breed originated in the Sindh

province of Pakistan and is widely kept for milk

production across India, Pakistan, Bangladesh, Sri

Lanka and other countries. They have been used for

crossbreeding with temperate (European) origin

dairy breeds in many countries to combine their

tropical adaptations (heat tolerance, tick resistance,

disease resistance, fertility at higher temperatures,

etc.) with the higher milk production found in

temperate regions.

MATERIAL AND METHODS

The data pertaining to milk production of purebred

Red Sindhi cows maintained at College of

Agriculture, Dhule spread over a period of 20 years

(1991 - 2010) was used for the present investigation.

Effect of age at �irst calving, season of calving, period

of calving and lactation order over production and

reproduction traits were studied by adopting the

least square technique (Harvey 1990). Duncan's

multiple range test (DMRT) as modi�ied by Kramer

(1957) was used for comparison between pairs of

means. Interrelationships between economically

important traits were studied.

RESULT AND DISCUSSION

The overall least square means for LL, DP, CI,

LMY and 300 DMY were 310.876 ± 6.07 days, 81.99 ±

4.78 days, 392.86 ± 7.92 days, 1816.66 ± 38.95 kg and

1820.56 ± 34.18 kg respectively.

The value of LL was higher than that reported by

Pundir et al (2007) in Red Sindhi cow. Lactation

order had highly signi�icant effect over LL.

Supportive result was reported by Bhoite and Kale

(1996) in BFG groups. Effect of age at �irst calving,

period of calving and season of calving was found to

be non signi�icant. In DMRT it was found that

lactation length gradually increased with advances in

lactation order. Cows in fourth lactation order had

signi�icantly higher lactation length of 341.34 ± 9.94

days than cows in �irst and second lactation order

having 287.69 ± 12.53 and 293.35 ± 11.09 days of

lactation length respectively. Further the lactation

length of cows in third and fourth lactation was at

par.

The overall least square mean of dry period and

calving interval was 81.99 ± 4.78 and 392.86 ± 7.92

days. Higher duration of dry period and calving

interval has been reported by Pundir et al. (2007).

Effect of age at �irst calving, season of calving, period

of calving and lactation order on both the traits was

found to be non signi�icant.

The overall least square means for LMY and 300 DMY

were 1816.66 ± 38.95 kg and 1820.56 ± 34.18 kg

respectively. Lower LMY and 300 DMY than the

current investigation have been reported by Rehman

and Khan (2012) in Sahiwal cattle, however higher

ABSTRACT

The overall least square means for lactation length (LL), dry period (DP), calving interval (CI), lactation milk

yield (LMY) and 300 days milk yield (300 DMY) in Red Sindhi cow were 310.876 ± 6.07 days, 81.99 ± 4.78

days, 392.86 ± 7.92 days, 1816.66 ± 38.95 kg and 1820.56 ± 34.18 kg respectively. The lactation length had

signi�icant effect over lactation milk yield, whereas, period of calving had signi�icant effect over lactation milk

yield and 300 days milk yield. The effect of age at �irst calving, season of calving, period of calving and lactation

order over all the other traits under study was non signi�icant.

Key words : Red Sindhi, Productive traits, Reproductive traits

*Corresponding author: [email protected]

Volume 5, Number 1-2, 2015

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Ta

ble

1. A

nal

ysis

of

vari

ance

fo

r p

rod

uct

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values for LMY and 300 DMY have been reported by

Kale (1984) in HF X G crosses. LMY and 300 DMY

were signi�icantly affected by period of calving. The

DMRT table revealed that there was gradual increase

in LMY and 300 DMY with advance in period of

calving. Signi�icantly higher LMY and 300 DMY were

recorded against P3 (2083.09 ± 63.05 and 2079.92 ±

55.33 kg resp.) than P1 (1574.59 ± 112.66 and

1562.65 ± 98.86 resp.) and P4 (1673.16 ± 79.59 and

1700.38 ± 69.84 kg resp.). Subsequently, values of

LMY and 300 DMY for group of cows that calved in

period P2 and P3 were at par, whereas cows calving

in period P1 and P4 were at par.

The correlation of lactation length with calving

interval and lactation milk yield was positive and

highly signi�icant. The correlation between dry

period and calving interval was found to be highly

signi�icant and positive. The correlation of calving

interval with LMY was positive and highly signi�icant.

REFERENCES

Bhoite, U.Y., Kale, K.M.1996. Production performance

of three breed Gir crosses. Indian Vet. J.

73(4):473- 474.

Harvey, W.R. 1990. Least squares analysis of data

with unequal subclasses number. USD. ARS.

20: 8.

Kale, K.M. 1984. Growth, reproduction and

production Performance of Gir cows and its

exotic crosses. Ph.D.Thesis, MPKV, Rahuri.

Krammer C. Y. (1957) Extension of multiple range

test to group correlated adjusted mean.

Biomatrics, 13:13-20

Pundir,R.K., Singh,P.K., Upadhaya, S.N. and Ahlawat S

P S (2007). Status, characteristics and

performance of Red Sindhi cattle. Indian J.

Anim. Sci., 77(8): 755-758.

Rehman Z. and Khan M.S., 2012. Environmental

factors affecting performance traits of

Sahiwal cattle in Pakistan. Pak Vet J, 32(2):

229-233.

Volume 5, Number 1-2, 2015

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Genetic evaluation of White Leghorn layers under reciprocalrecurrent selection

1Ramesh Kumar*, S Kalra, Satbir Singh and B ParkashKrishi Vigyan Kendra, Jind -126102 (Haryana) India

INTRODUCTION

The primary objective of a poultry breeder is to alter

gene frequencies and distribution by employing

various mating systems/selection methods to

improve different traits of economic importance that

will maximize the ef�iciency of production and

increase pro�itability. There are different methods of

selection, each with several variants. RRS Reciprocal

Recurrent Selection method of selection increases

the frequency of both additive and non-additive

genes, hence improve pure-line as well as cross-line

performance. The main reason for this is that

crossbreds often exhibit heterosis that indicates the

existence of non- additive effects and the two

populations under reciprocal recurrent selection do

not have identical gene frequency which causes the

covariance between them to be small or negative.

Reciprocal recurrent selection leads to a high

performance for lowly heritable and heterotic traits.

Crossbreeding is a standard practice in poultry

breeding programs as a way of exploiting heterosis.

Furthermore, the goal of breeding is not to maximize

heterosis, but to maximize overall pro�itability in the

commercial cross, the parents and the pure lines.

Considering cross-bred and pure-bred performance

as two separate, but correlated traits offers an

elegant way to take environmental effects into

account.

Instead of describing theory of RRS kindly give

objective of your study and also give some reference

in introduction part which are related with earlier

studies).

ABSTRACT

Present study revealed that crossbreds were marginally superior in most of the performance traits than the

purebreds. AFE of purebreds was lower than observed for crossbreds in all generations except G , G and G 4 5 6

generations.The EN was more during the initial three generations of study whereas it declined sharply in the

fourth and sixth generations. No de�inite trend was observed for the difference in EW of two reciprocal

crosses in all the generations under study. EN was found to be more important than EW in determining the

EM. Differences in the mean over the generations may be accounted for by the effect of selection and

environmental factors.Heritability estimates for BW , BW and AFE were moderate to high, but EN was low 20 40

heritable. Heritabilities of EM, EM/BW and EM/AFE were moderate indicating that some form of family 20

selection may be effective for their improvement. Standard errors of heritability estimates were small

suggesting that a reasonably high degree of reliance can be placed on these estimates. Large standard errors

of heritabilities of traits of crossbreds than the purebreds might be due to smaller population size in

comparison to purebred strains. Body weight, age at �irst egg and egg number were negatively correlated with

each other both at genetic and phenotypic levels. Egg weight was positively correlated with body weights at

phenotypic level both in purebreds and crossbreds but negatively genetically correlated in purebreds and

reverse was observed in crossbreds. Most of the phenotypic correlations were highly signi�icant both in

purebreds and crossbreds. It might be concluded that heavier birds lay large sized eggs but higher weight

during laying period is not a desirable proposition. Results suggest the use of RRS selection schemes for

further improvement of egg production and its component traits of hybrid layer.

Key words : Genetic evaluation, egg production, hybrid layer, RSS1Present Address: KVK, Sangrur (Punjab)

* Corresponding author : [email protected]

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MATERIALS AND METHODS

Data pertaining to the present study were collected

from records spreading over nine generations i.e.

1994-95 to 2002-03 for the performance traits of

both strains (which both strains is not clear, pl give

name and in one line details of strains)and their

crosses. The chicks of all the four genetic groups

(H×H, C×C, H×C and C×H) were brooded and reared

hatch-wise. The progenies were produced in

different hatches at weekly intervals during the

month of April and May each year. All the chicks were

pedigreed, wing-banded at the time of hatching and

reared hatch-wise using standard managemental

practices. Cockerels were separated from the pullets

at eight weeks of age. At 20 weeks of age, the body

weights were recorded and pullets were housed in

layer houses. Trap-nest records of each pullet were

maintained to record the age at �irst egg and egg thproduction upto 40 weeks of age. During 40 week,

three eggs from each pullet were weighed and

averages of these were considered as egg weight of

the pullet. At 40 weeks of age, body weights of hens

were also recorded. Standard managemental

practices were followed during the course of present

study. The performance traits viz. body weight at 20

(BW ) and 40 weeks age (BW ), age at �irst egg 20 40

(AFE), egg number upto 40 weeks age (EN) and egg

weight during 40 weeks of age (EW) were recorded

on individual purebred and crossbred pullets.

Genetic and phenotypic parameters of the traits of

purebred and crossbred were estimated from sire

component of variances and covariances. The

performance traits viz BW and BW AFE, EN and 20 40,

EW were recorded on individual purebred and

crossbred pullet. Egg mass upto 40 weeks of age

(EM), ratio of egg mass to body weight at 20 weeks

age (EM/ BW and ratio of egg mass to age at �irst 20)

egg (EM/AFE) were calculated for individual pullet.

Generation wise, genetic and phenotypic variances

and covariances among the traits, least square

means, heritabilities and correlations among traits of

purebreds and crossbreds were estimated using

Mixed Model Least Squares Maximum Likelihood

Computer Programme of Harvey (1987).

RESULTS AND DISCUSSION

Generation wise least squares means alongwith

standard error for body weight at 20 and 40 weeks

(g) , age at �irst egg (days) and egg number of

different genetic groups are given in Table 1. The

results depicted that crossbred pullets were

signi�icantly heavier at 20 weeks of age than the

purebred pullets in G and G but statistically non 1 8

signi�icant in G generations only. At 40 weeks of age, 4

crossbred pullets were heavier than purebred

pullets in all generations except G , G and G 2 3 9

generations. BW for purebreds ranged from 20

1202.53±2.89 to 1316.81±3.94g and the crossbreds

ranged from 1202.21±12.11 to 1311.33±7.19g. The

corresponding �igures for BW were 1406.36±10.25 40

t o 1 6 6 7 . 0 4 ± 5 . 5 9 g a n d 1 4 6 0 . 3 7 ± 7 . 7 4 t o

1713.25±7.41g, respectively. Sakunthala (2001) and

Singh (2001) reported similar body weights at both

ages in purebred strains con�irming the present

results. The results on crossbreds, body weights at

both ages are in agreement with those of Singh

(2001). On the contrary, Brah et al. (2002) reported

lower BW and BW weeks age in purebred and 20 40

crossbred groups while Yahaya et al. (2009) reported

higher values for these traits (BW andBW ) than 20 40

observed in this study.

Average AFE of purebred pullets was signi�icantly

lower than observed for the crossbred pullets in all

generations except G , G and G generations. AFE of 4 5 6

purebred and crossbred pullets ranged from

135.04±0.24 to 162.11±0.68 days and 143.78±0.85

to 163.44±0.79 days, respectively (Table 1). Lower

AFE in G generation compared to other generations 6

might be due to indirect selection as the criterion of

selection was EN to �ixed age (280 days).Similar

�indings to the present results have also been

reported earlier in literature (Sakunthala , 2001 and

Singh, 2001). Higher values for this trait in purebreds

and crossbreds were reported by Yahaya et al (2009).

The average EN ranged from 55.28±0.63 to

81.48±0.75 and 57.02±1.04 to 81.25±0.71 in

purebreds and crossbreds, respectively (Table 1).

Difference in the performance of two reciprocal

crosses suggests that a particular strain should be

used as male line and the other as female line for

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producing a commercial hybrid layer. Brah et al.

(2002) reported higher EN upto 40 weeks of age for

purebreds than the crossbreds which is contrary to

the present results. However, Yahaya et al (2009) and

Momoh et al (2010) reported higher egg production

in crossbreds than purebreds and are in agreement

to the present study.

The egg production declined during fourth and sixth

generation. The main reason of this decline may be

due to Gumboro outbreak during……. Year? in this

population causing death of high producing birds.

Another possible reason might be that while

selecting the pullets, emphasis on egg weight was

also given in later generations thus causing decline in

egg production because of negative genetic

correlation between these two traits.

Average EW was signi�icantly higher for the

crossbreds than the purebreds in generations G and 1

G only and signi�icantly lower in G , G and G . In the 2 3 6 7

remaining generations the EW of purebreds and

crossbreds were similar. The averages for EW in

purebreds ranged from 49.15±0.18 g to 53.70±0.18 g

and 48.06±0.32 g to 53.21±0.22 g in crossbreds over

the generations (Table 2) which is in close

conformity with the �indings of Singh (2001),Brah et

al. (2002) and Momoh et al (2010). Yahaya et al.

(2009) reported superiority of crossbreds over

purebreds in two generations of RRS.

Average EM was higher in crossbreds than the

purebreds in the generation G and signi�icant in G , 1 3

G , G and G generations. The averages for EM ranged 5 8 9

from 2936.65±33.06 g to 4213.35±31.26 g and

2887.89±60.74 g to 4080.74±35.93 g in purebreds

and crossbreds, respectively (Table 2). Momoh et al

(2010) reported lower values than the present study

for this trait in purebreds but higher values in

crossbreds. Highest EN (Table 1) and EM (Table 2) in

generation G indicated that EN is more important 2

than EW in determining the EM.

Ratio of EM/BW ranged from 2.23±0.03 to 2 0

3.44±0.03 in purebreds and 2.21±0.05 to 3.37±0.03

in crossbreds, respectively (Table 2). The ratio was

higher for the crossbreds in generations G and 1

signi�icant in G G , and G only and lower in rest of the 3, 5 9

generations. Ratio of EM/AFE ranged from

20.01±0.31 to 31.30±0.25 in purebreds and

20.27±0.52 to 26.77±0.26 in crossbreds (Table 2).

Crossbreds were superior to purebreds in

generations G , G and G for this trait. From the above 4 5 7

results, it may be concluded that in general

crossbreds were slightly superior to the purebreds

for most of the performance traits. Differences in

generation means for different traits may be

accounted for by the effect of both selection and

environmental factors.

Heritability : Heritabilities estimated from sire

component of variance pooled over generations

along with their standard errors for performance

traits of purebred and crossbreds are presented in

Table 3.

The results showed that heritability estimates for

BW and BW age was medium for the purebreds 20 40

(0.391±0.043, 0.352±0.054) and high for crossbreds

(0.418±0.034, 0.444±0.089). The present results are

in con�irmation with the �indings of Shakunthala

(2001) for purebreds at 20 weeks age. The reported

estimates of heritability of crossbred in present

study are lower for both traits than those of Singh

(2001) but higher than reported by Yahaya et al

(2009).

Medium heritability of BW and BW has also been 20 40

reported earlier (Chatterjee et al, 2008). The results

of present study indicated that BW for crossbreds is 40

highly heritable. The higher heritability of crosses

over pures for these traits is caused by higher genetic

variation and lower environmental variation. Higher

heritability estimates in crosses than in pures were

also reported by Yahaya et al (2009) whereas

Pirchner (1976) observed only slight differences in

heritabilities between crosses and pures. The excess

of sire component heritability in crosses over the

pures for body weight (as reported in literature)

showed that body weights are in�luenced by non-

additive genetic effects. Thus, the magnitude of

heritability of a particular cross was more dependent

on the male-parent than that of female-parent

strain.

The pooled estimates of heritability for AFE were

found to be 0.427±0.099 and 0.565±0.106 in

purebreds and crossbreds respectively. Higher

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Volume 5, Number 1-2, 2015

28

Table1. Generation wise least squares means along with standard error for body weight at 20 and 40 weeks (g),

age at �irst egg (days) and egg number of different genetic groups

Purebreds Crossbreds

Gener- 20wk (gm) 40wk (gm) AFE (days) EN 20wk (gm) 40wk (gm) AFE (days) EN

ations

1. 1202.53a±2.89 1593.21a±3.86 147.20a±0.27 75.04a±0.45 1217.06b±3.71 1599.08a±4.21 154.08b±0.34 76.59a±0.98

(478) (328)

2. 1223.93a±3.14 1561.37a±3.58 135.04b±0.24 81.48a±0.75 1212.67a±5.58 1550.77a±4.75 153.20a±0.46 78.76b±0.68

(628) (300)

3. 1275.25a±4.15 1646.34a±4.51 138.88b±0.40 65.60b±0.74 1202.21b±12.11 1597.06b±11.55 146.86a±1.12 72.35a±1.84

(358) (68)

4. 1230.61a±4.28 1553.13b±4.97 151.16a±0.47 58.96a±0.66 1239.63a±5.73 1582.94a±8.33 143.82b±0.48 58.32a±0.93

(294) (136)

5. 1295.25a±2.75 1617.33a±4.47 159.70a±0.33 76.74b±0.51 1289.33a±3.72 1625.00a±5.85 154.35b±0.51 81.25a±0.71

(472) (240)

6. 1316.81a±3.94 1667.04b±5.59 145.87a±0.54 55.28a±0.63 1311.33a±7.19 1713.25a±7.41 143.78a±0.85 57.02a±1.07

(285) (83)

7. 1311.02a±3.67 1541.57a±4.99 145.17b±0.36 65.68a±0.55 1242.70b±3.37 1555.75a±8.22 149.14a±0.56 62.86b±0.91

(362) (174)

8. 1225.91b±10.34 1406.36b±10.25 142.96b±0.66 61.06b±1.06 1290.75a±11.56 1479.79a±10.19 159.00a±0.62 64.84a±0.90

(110) (146)

9. 1222.28a±4.51 1479.70a±6.31 162.11a±0.68 66.33b±0.88 1212.48a±5.64 1460.37a±7.74 163.44a±0.79 72.51a±0.92

(267) (246)

Overall 1255.74a±1.51 1575.93a±1.98 145.22b±0.22 72.03b±0.30 1237.36b±2.36 1561.49b±2.91 149.82a±0.30 73.86a±0.36

(3254) (1721)

Figures in parentheses are the number of observations. Means bearing different superscripts (among genetic groups and crosses separately) differ signi�icantly (P<0.05)

Table 2. Generation wise least squares means along with standard error for egg weight (gm), egg mass (gm), ratio of egg

mass to body weight at 20 weeks age and ratio of egg mass to age at �irst egg of different genetic groups

Purebreds Crossbreds

Gener- 20wk (gm) 40wk (gm) AFE (days) EN 20wk (gm) 40wk (gm) AFE (days) EN

ations

1. 51.32a±0.12 3898.07a±31.28 3.27a±0.03 26.50a±0.25 52.68b±0.14 4056.62a±38.22 3.33a±0.03 26.34a±0.30

(478) (328)

2. 50.92b±0.10 4213.35a±31.26 3.44a±0.03 31.30a±0.25 51.86a±0.08 4072.85b±31.02 3.37a±0.03 26.77b±0.26

(628) (300)

3. 50.42a±0.17 3274.87b±30.14 2.57b±0.02 23.76a±0.26 48.06b±0.32 3465.28a±83.88 2.89a±0.07 23.75a±0.64

(358) (68)

4. 53.70a±0.18 3165.74a±37.15 2.58a±0.03 21.04a±0.27 53.21a±0.22 3106.04a±52.36 2.51a±0.04 21.65a±0.39

(294) (136)

5. 50.83a±0.14 3897.16b±26.96 3.01b±0.02 24.49b±0.19 50.32b±0.21 4080.74a±35.93 3.17a±0.03 26.55a±0.27

(472) (240)

6. 52.88a±0.14 2936.65a±33.06 2.23a±0.03 20.37a±0.29 50.54b±0.23 2887.89a±60.74 2.21a±0.05 20.27a±0.52

(285) (83)

7. 52.79a±0.13 3465.04a±29.04 2.65a±0.02 24.05a±0.25 51.12b±0.19 3209.02b±46.24 2.59a±0.04 21.60b±0.34

(362) (174)

8. 50.68a±0.30 3101.93b±57.47 2.54a±0.05 21.81a±0.44 50.01a±0.27 3249.63a±45.05 2.53a±0.04 20.53b±0.32

(110) (146)

9. 49.15a±0.18 3271.54b±43.55 2.68b±0.04 20.01b±0.31 49.07a±0.20 3554.11a±45.73 2.94a±0.04 22.02a±0.35

(267) (246)

Overall 51.43a±0.06 3688.27b±14.49 2.95b±0.01 25.78a±0.12 51.00b±0.08 3764.77a±19.41 3.06a±0.02 25.47a±0.16

(3254) (1721)

Figures in parentheses are the number of observations. Means bearing different superscripts (among genetic groups and crosses separately) differ signi�icantly (P<0.05)

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29

estimates of heritability in crossbreds than in

purebreds were reported by Singh (2001). The

�indings of this study resembles with the reports of

Chatterjee et al. (2000, 2008) for purebreds. The

pooled heritability estimates over generations were

lower for purebreds (0.255±0.054) than the

crossbreds (0.324±0.090). Singh (2001) and

Ravikumar (2003) reported heritability of part year

egg production ranging from 0.02±0.17 to 0.35±0.23

which are in agreement with the present results.

The higher pooled heritability estimates in

crossbreds than in the purebreds were reported by

Singh (2001). Contrary to the present results, higher

heritability estimates in purebreds than in

crossbreds have been reported by various workers

(Chaudhary et al., 1997). The heritability obtained in

the present study as well as reported by earlier

workers indicates that egg number is low to

moderate heritable and can be improved by

following some form of combined selection. The

lower heritability estimates are indicative of

increased role of various environmental in�luences.

The low magnitude of heritability estimates of EN in

purebreds as compared to other traits indicates two

possibilities. Firstly, it could be because of the fact

that egg production, being a �itness trait, its

heritability estimates were low. Secondly, continued

selection for egg production practiced during the last

two decades could have been responsible for a

gradual reduction in the genetic variation in this

trait.

Heritability estimates for EW were higher in

crossbreds than purebreds suggesting that this stock

had more additive genetic variance for further

utilization through selection. The heritability

estimates were 0.286±0.060 and 0.369±0.061 in

purebreds and crossbreds respectively. The

estimates obtained by Besbes and Gibson (1999)

were higher than those observed in the present

study. On the contrary, lower heritability estimates

were reported by Chaudhry et al. (1997) both in

purebreds and crossbreds. The higher estimates of

heritability in crosses than in purebreds have also

been reported earlier (Singh, 2001).

The heritability estimates for EM were 0.276±0.058

and 0.408±0.083 in purebreds and crossbreds

respectively. These estimates are lower than

reported by Thangaraju and Ulaganathan (1990)

(0.809±0.183 in Forsgate strain and 0.683±0.166 in

Meyer Strain). Medium to high heritability of this

trait indicates the possibility of improvement

through some form of intra-population selection.

The estimates of heritability for ratio trait

(EM/BW ) were also higher in crossbreds than 20

purebreds like other performance traits. The

estimates were 0.284±0.060 and 0.365±0.077 in

purebreds and crossbreds, respectively. On the

contrary, Thangaraju and Ulaganathan (1990)

reported higher estimates of heritability for this trait

(0.637±0.155 and 0.953±0.209 in Forsgate and

Meyer strains, respectively). The present results

suggest that this trait can be improved effectively by

mass selection.

Heritability estimates of ratio trait (EM/AFE) were

estimated as 0.276±0.075 and 0.363±0.076 in

purebreds and crossbreds, respectively. These

estimates were also higher in crossbreds than

purebreds. These results are of low magnitude than

those obtained by Thangaraju and Ulaganathan

(1990) for purebreds (0.872±0.192 in Forsgate and

0.418±0.122 in Meyer strain).

Based on the present �indings, it may be concluded

that heritability estimates for BW , BW and AFE 20 40

were moderate to high. The standard errors were

small, suggesting that a reasonably high degree of

reliance can be placed on these estimates. However,

the standard errors were relatively larger in the

crossbreds which may be because of small

population size as compared to the purebreds. EN is

low heritable and to some extent may be in�luenced

by non-additive gene action. Heritability estimates of

EM and its ratio traits were moderate indicating that

some form of family selection may be effective for

their improvement.

Heritability estimates of all the traits under study

were higher for the crosses than the purebreds

s u g g e s t i n g t h e b u ff e r i n g q u a l i t i e s o f t h e

heterozygous genotypes in relation to a changing

environment. Also the additive genetic variation

observed among crossbred progenies may contain

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30

Table 3. Heritabilities (±SE) of performance traits of purebreds and crossbreds

estimated from sire component of variances

Traits Purebreds Crossbreds

BW20 0.391±0.043 0.418±0.034

BW40 0.352±0.054 0.444±0.089

AFE 0.427±0.099 0.565±0.106

EN 0.255±0.054 0.324±0.090

EW 0.286±0.060 0.369±0.061

EM 0.276±0.058 0.408±0.083

EM/BW20 0.284±0.060 0.365±0.077

EM/AFE 0.276±0.075 0.363±0.076

Table 4. Genetic correlations along with standard error among performance traits of purebreds estimated fromsire component of variances and covariances

Traits BW40 AFE EN EW EM EM/BW20 EM/AFE

BW20 0.522±0.206 0.048±0.248 0.020±0.295 –0.158±0.245 –0.161±0.284 –0.354±0.294 –0.140±0.261

BW40 –0.550±0.194 0.346±0.243 0.004±0.248 0.320±0.236 0.197±0.247 0.408±0.205

AFE –0.866±0.173 0.039±0.206 –0.883±0.161 –0.855±0.158 –0.945±0.135

EN –0.237±0.160 0.969±0.015 0.917±0.038 0.963±0.022

EW 0.008±0.241 0.132±0.240 0.015±0.221

EM 0.980±0.011 0.988±0.010

EM/BW20 0.967±0.019

Table 5. Genetic correlations along with standard error among performance traits of crossbreds estimated from

sire component of variances and covariances

Traits BW40 AFE EN EW EM EM/BW20 EM/AFE

0.506±0.134 0.105±0.180 0.213±0.176 0.012±0.190 0.236±0.175 0.023±0.186 0.179±0.180

BW40 –0.487±0.126 0.095±0.157 0.466±0.131 0.199±0.153 0.068±0.160 0.375±0.139

AFE –0.205±0.151 0.440±0.137 –0.128±0.155 –0.128±0.156 –0.255±0.152

EN –0.439±0.141 0.975±0.008 0.960±0.014 0.871±0.038

EW 0.233±0.157 0.266±0.156 0.064±0.166

EM 0.975±0.009 0.925±0.023

EM/BW20 0.903±0.031

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31

Table 6. Phenotypic correlation along with standard error among performance traits of purebreds

Traits BW40 AFE EN EW EM EM/BW20 EM/AFE

0.648**±0.009 –0.119**±0.011 0.115**±0.008 0.028±0.012 0.093*±0.07 0.254**±0.00 8 0.027±0.009

BW40 –0.233***±0.012 0.024±0.011 0.162**±0.011 0.057±0.008 –0.118**±0.00 7 0.106±0.009

AFE –0.434**±0.010 0.055±0.009 –0.450**±0.008 –0.419**±0.008 –0.656**±0.009

EN –0.443**±0.011 0.973**±0.012 0.935**±0.008 0.943**±0.007

EW 0.232**±0.011 0.224**±0.011 0.231**±0.012

EM 0.962**±0.018 0.965**±0.019

EM/BW20 0.925**±0.015

* = P±0.05, ** = P±0.01

Table 7. Phenotypic correlation along with standard error among performance traits of crossbreds

Traits BW40 AFE EN EW EM EM/BW20 EM/AFE

0.685**±0.008 –0.212**±0.011 0.188**±0.009 0.050±0.011 0.111*±0.008 0.244**±0.007 0.129**±0.008

BW40 –0.264**±0.012 0.068±0.009 0.252**±0.011 0.148**±0.009 –0.109*±0.008 0.209**±0.007

AFE –0.101*±0.008 0.142**±0.009 –0.136**±0.011 –0.091*±0.008 –0.417**±0.009

EN –0.224**±0.009 0.949**±0.017 0.894**±0.015 0.898**±0.011

EW 0.086±0.007 0.060±0.008 0.116**±0.007

EM 0.933**±0.018 0.954**±0.017

EM/BW20 0.881**±0.016

* = P±0.05 ** = P±0.01

both the additive genetic variation found in the

purebred lines plus the purebred's non-additive

genetic variation which is seen as additive genetic

variation in the crossbred. From the results it may

also be inferred that non-additive genetic variation

existed for various components of egg laying

productive traits. This type of genetic variation may

be exploited through some sort of crossbred

selection schemes.

Genetic and phenotypic correlations : Genetic and

phenotypic correlations among various traits in the

present investigation were estimated by sire

component of variance and covariances and are

presented in Tables 4 to 7 respectively.

Correlation of body weight with other traits :

Genetic correlation of BW was found to be negative 20

with EW, EM, EM/ BW and EM/AFE in purebreds 20

while positive with all other traits in both purebreds

and crossbreds. The phenotypic correlation between

BW and AFE were highly signi�icant and negative 20

but low in magnitude both in purebreds and

crossbreds. Kumar (2001) also reported negative

genetic correlation between BW and EW while 20

several authors reported in reverse direction.

Negative genetic association of BW with AFE and 20

EN and phenotypic correlations between BW and 20

AFE were also reported to be negative and low both

in purebreds and crossbreds (Singh, 2001). Genetic

and phenotypic correlations between BW and AFE 40

were observed to be negative both in purebreds and

crossbreds. On an average, magnitudes of genetic

correlation between these traits were low in

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32

crossbreds compared to purebreds. The results

indicated that pullets with higher BW attained sexual

maturity earlier, con�irming the fact that optimum

BW is also important in layer �locks too.

Genetic and phenotypic correlations of BW and 20

BW with EN were found to be positive both in 40

purebreds and crossbreds. Yahaya et al. (2009) also

reported positive genetic association between BW 20

and EN. On the basis of the present �indings and

reports available in the literature, it may be

concluded that pullets which attain more weight

before sexual maturity produce more eggs but more

body weight during laying is not desirable as heavy

birds are likely to produce less number of eggs.

The genetic correlation between BW and 20

EW was negative in purebreds but positive in

crossbreds but of low magnitude. However,

phenotypic correlations of BW and BW with EW 20 40

were positive in purebreds as well as in crossbreds.

From these results, it may be concluded that heavier

birds are likely to lay large sized eggs.

Correlation of age at �irst egg with other traits : T h e

genetic and phenotypic correlations between AFE

and EN were found to be negative for both purebreds

(-0.866±0.173 and -0.434±0.010) and crossbreds (-

0.205±0.151 and -0.101±0.008). Most of the

phenotypic correlations of AFE with other traits

were highly signi�icant (P±0.01) both in purebreds

and crossbreds. Similar estimates between these

traits have also reported by Singh (2001), Khalil et al

(2004) and Anees et al (2010). Contrary to the

present �indings, Singh (1994) reported positive

genetic correlation between these traits. From

present results it may be inferred that direct

selection for high EN may lower down the age at

sexual maturity concomitantly. The negative

genotypic and phenotypic correlation among these

traits indicated that early maturing pullets laid more

eggs upto 40 weeks of age. Hence, strong negative

association between these traits will be bene�icial to

the breeder as long as there is no adverse impact on

egg weight.

The genetic and phenotypic correlation between

AFE and EW were positive in both purebreds

(0.039±0.206 and 0.055±0.009) and crossbreds

(0.440±0.137 and 0.142±0.009). Chatterjee et al.

(2000) reported low correlation between AFE and

EW. However, negative associations between these

traits were reported by Singh (2001) and Shad et al

(2007).

The genetic as well as phenotypic correlations of AFE

with EM, EM/ BW and EM/AFE were found to be 20

negative in both purebreds and crossbreds. The

estimates of correlation of AFE with other traits were

higher in purebreds than in crossbreds.

Correlation of egg number with other traits :

Negative genetic and phenotypic correlations

between EN and EW in both purebreds (-

0.237±0.160 and -0.443±0.111) and crossbreds (-

0.439±0.141 and -0.224±0.009) were observed.

Present results are in agreement with the �indings of

earlier workers (Singh, 2001; Chatterjee et al., 2008

and Yahaya et al, 2009). On the contrary, Kumar et al.

(2001) reported positive genetic correlation

between these traits. Magnitude of genetic

correlation between these traits was higher in

crossbreds than in purebreds. From the present

results, it may be concluded that high laying pullets

will produce comparatively small sized eggs and

therefore, to improve simultaneously both the traits,

some specialized selection programs should be

practiced.

EN was highly positively correlated with EM, EM/

BW and EM/AFE, both at genetic and phenotypic 20

levels in purebreds as well as in crossbreds.

Correlation of egg weight with other traits :

Positive but low genetic and phenotypic correlation

between EW and EM were observed both in

purebreds and crossbreds. Similar trend was

observed for the correlation between EW and EM/

BW and EM/AFE in both purebreds and crossbreds. 20

The magnitude of genetic correlation was higher in

crossbreds than the purebreds. Standard errors of

genetic correlations were large indicating that

estimates are extremely variable, possibly due to

inadequate population sizes. Thangaraju and

Ulaganathan (1990) reported negative genetic

correlations of EW with EM and EM/AFE in Forsgate

strain but their results of Meyer strain were similar

to the present �indings.

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33

Correlation among egg mass, ratio of egg mass to

body weight at 20 weeks and ratio of egg mass to age

at �irst egg : Positive high genetic and phenotypic

correlations were observed among these three

traits both in purebreds and crossbreds. These

results are in conformity with those reported by

Thangaraju and Ulaganathan (1990).

Genetic correlations of body weights with

AFE and EW were negative in purebreds but

positive between BWs and EW in crossbreds.

Genetic correlation between AFE and EN was

negative both in purebreds and crossbreds.

Genetically AFE was positively associated with EW,

but negatively with EM and both ratio traits in

purebreds and crossbreds. Positive but low genetic

correlation of EW with EM and both ratio traits was

observed both in purebreds and crossbreds.

Phenotypic correlations of BWs with AFE were

negative and highly signi�icant both in purebreds

and crossbreds. Positive and highly signi�icant

correlation of BW with EW was also observed. 40

Phenotypic correlations of AFE with EN, EM and

both ratio traits were negative and highly

signi�icant both in purebreds and crossbreds.

Negative and highly signi�icant phenotypic

correlation was found between EN and EW both in

purebreds and crossbreds. High positive

correlation between EN and EM suggested that

selection for EM may bring about concomitant

increase both in EN and EW unlike selection for EN

alone causing a decrease in EW as correlated

response. Most of the correlations among all the

traits under study were highly signi�icant (P±0.01)

both in purebreds and crossbreds.

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