Reproductive Management of Dairy Cows with Particular Reference to Organic Systems

Michael G Diskin & Frank Kelly

Animal Production Research Centre, Teagasc,

Mellows Campus, Athenry, Co. Galway.

Holstein-Fresian cattle

Grolier Electronic Publishing, Inc.

Reproduction

Biological Efficiency

Production Efficiency

Profitability

Overall Requirements for Organic Milk Production Systems

• Compact seasonal calving patterns,

• Maximal production from grazed grass,

• Low involuntary culling rates

• Continuous genetic improvement of the herd

Reproductive Targets

Low Culling Rate for infertility: < 5%.

Calving Interval: 365 day calving-to-calving.

Compact Calving: 90% calved in < 80 days

Improving Reproductive efficiency

Shortening Post-partum interval

Submission Rates

Conception Rates

Post-Partum Interval

Dairy Cows Mean=26 days(15-50 Days)

Beef Cows Mean=55 days(25-180 Day)

Aim to have a calf per cow

per year with peak lactation

to correspond with peak

grass growth

Postpartum reproduction - cattle

To Ensure Rapid Onset of Oestrous Cycles Post Calving

• Cows calve in a moderate BCS

• Ensure high DM intakes post calving & minimise BCS loss – Minimise Negative Energy Balance (NEB)

• Calve heifers early

• Consistently use Sire with strongly positive sub indices for Fertility

Heat Detection Rate

Conception Rate

Pregnancy Rate

Main Factors Affecting Pregnancy Rate

The Effect of Different Heat Detection and Conception Rate on % of Herd Pregnant at 90 Days After Onset of Breeding Season

Conception rate

60 50 40 30

90 96 91 83 71

70 91 82 73 61

50 76 68 59 48

HeatDetectionRate %

40 67 59 50 4059

Heat Detection

Breeding

• Use of AI

• Heat detection

• Factors affecting conception rate

Primary Sign of Heat

Secondary Signs of Heat• Sliming

• Restlessness

• Mounting activity

• Trailing other cows

• Bellowing

• Mounting or dirt marks

• Skin Marks

• Met-oestrous bleeding

Mucous vaginal discharge

Chin resting

Factors affecting the Expression of heat

Teagasc, Athenry Results

Effect of underfoot surface on number of mounts received per heifer during standing heat.

2030

4048

0

20

40

Slats Straw Plastic Pasture

Underfoot surface

No.

Mou

nts

Effect of underfoot surface on duration of heat

8.6

14.212.3

14.7

0

5

10

15

20

Slats Straw Plastic Pasture

Underfoot surface

Hou

rs

Effect of number of heifers in heat simultaneously on the number of mounts

received heifer during standing heat.

17

29

40

0

20

40

1 2 3

No. Heifers in Heat Simultaneously

No

. Mo

un

ts

Duration of Standing Heat

• Average = 8 -14 hours (Range 3-30 hours)

• Similar for cows and heifers

• Range 3-30 hours

• Interruptions in standing activity

Pattern of heat Onset

% of cows first observedat

7:00 10:00 13:00 16:00 23:00

47% 5% 5% 20% 20%

Improving heat detection

• Commitment and understanding heat behaviour

• Tail paint

• Oestrus Alert Patches

• Teaser Bull

Teaser Bulls• Use yearling bull• Vasectomise 6 weeks before intended

use• Fit with chin-ball 2-3 weeks before

introduction to herd• Castrate or sell at end of breeding

season

FEFC88FFEFC88F1

Management Factors Affecting Conception Rate

Reproductive Outcomes British Friesian vs Holstein Friesian

10%

10+%

Calving rate55%

Calving rate40%

EarlyEmbryo Death 28% Early

Embryo Death 43%

Fertilisation Failure

Late Embryo Mortality 7% 7%

British Friesian 1980 Holstein Friesian 2005

Change in BCS and conception rate

• 10-15% decline in conception for each 0.5 unit change in BCS between calving and AI.

Effect of Calving to Service Interval on Conception Rate

Calving-to-Service Interval(Days)

1-20 21-40 41-60 61-80 >80

CR% 0 30 54 63 72

Effect of AI timing on Conception Rate

010203040506070

<6 h 6-12h 12-18h 18-24h >24h

Interval from Detected Heat to AI

Con

cepi

on R

ate

(%)

Effect of Calving Difficulty on Conception Rate

0

20

40

60

1 2 3 4 5 6

Calving Difficulty Score

Con

cep

tion

Rat

e (%

)

Long-term improvement of cow fertility

• Use High EBI (Economic Breeding Index sires)

• EBI Reproduction: Calving interval

Cow survival

Production: Yield fat + Protein

Summary -1

Calve cows in a moderate BCS Minimise BCS loss in early lactation. Have cows gaining in BCS at breeding. Have heifers well-grown (350-380 kg)

at 15 months. Breed to calve early. Minimise the risk of calving difficulty .

Summary -2

Increase submission rates by paying particular attention to heat detection.

Use tail-paint. Carry out pre-breeding heat detection.

Ensure that the semen used is of high fertility Use AI Sires with negative values for calving

interval and positive values for survival Correct AI technique Inseminate cows at the correct time.