View
221
Download
1
Category
Tags:
Preview:
Citation preview
Livestock and Poultry Evaluation
Animal Science II
Performance Data Beef Cattle Reproductive performance
– Conception rate– Calf crop percentage (born)– Calf crop percentage (weaned)– Calving interval
• length of time between calving for each cow in the herd that is breeding age
Performance Data Beef Cattle Reproductive performance
– Birth weight related to calving difficulty
– Fertility testing of bulls• should be tested before each breeding
season
Performance Data Beef Cattle
Calving difficulty score
1- No difficulty. No assistance2- Minor difficulty. Some assistance3- Major difficulty. Mechanical assistance4- Cesarean birth or other surgery5- Abnormal presentation
Performance Data Beef Cattle Bull Performance
– Information varies from breeder to breeder
– 15-20 different types of data• Average daily gain• Scrotum circumference
Performance Data Beef Cattle Growth and Gain Performance
– Weaning weights adjusted to 205 days
– Yearling (365 days) and long yearlings (452 or 550)
– Post weaning rate of gain (minimum of 140 days on test)
– Weight per day of age
Performance Data Beef Cattle Weaning Weights adjusted to 205
– standard basis
Actual weight - Birth weight
Age in daysX 205 days + Birth weight
Performance Data Swine
Sow Productivity– Fertility (number of pigs per litter)– Litter weight at weaning
• best overall measure of sow productivity because it is affected by the number of pigs weaned and milk production
Performance Data Swine Growth Rate
– Adjusted days to 230 pounds– Rate of gain=pounds of gain on test/ days
on test– Feed efficiency= amount of feed/ amount
of gain– Carcass merit
• Backfat thickness (less is better)• Loin-eye area• Percentage of lean cuts
Performance Records Poultry
Past performance– Pedigree
• Gives records of ancestors
Present performance on individuals and siblings
Rate of gain and feed efficiency
Production Records
Heritability Estimates – Vary by trait ranging from 0 to 70– Fertility is 0 to 10 percent
• management affect more than genetics
– Loin-eye area is fastest improved by selective breeding• 70% in cattle• 50% in swine
Production Records
Sow productivity index– uses a formula that included the
number of live pigs born and adjusted 21-day litter weight for individual sow comparison
Production Records
Use of Data Records– In most cases the highest number is
better– Exceptions:
• birth weight• calving difficulty• backfat thickness in swine
Production Records
Estimated Breeding Value (EPV)– Estimate of the animal true breeding
ability– Expressed as a percentage to the
average of the animal to which the bull is compared• 105 is 5% above the average• 95 is 5% below the average
Production Records
Expected Progeny Difference (EPD)– Bulls can only transmit 1/2 of its
superiority as shown on its EPV.– If the EPV is 106 that is (106-100=6)
which is then halved to make three percent (6/2=3)
– Females transmit the other half
Production Records
Pedigree Index (PI)– The closer the animal is to the bull
being evaluated the more effect their performance traits have
Poultry Production Records
The type of record use to select by pedigree are past performance records
Present performance records are used to select physical appearance
Judging Livestock
Physical Characteristics– Confirmation
• Appearance including frame size, fat, etc.
– Structural soundness• More important today because of
confinement operations with concrete floors
– Especially swine and dairy
Judging Livestock
Commercial producers are more interested in performance records while breeders are concerned with pedigrees and breed characteristics
Judging Poultry
Most producers have no input in selection because they are contract farmers
Broilers– Must be healthy and well fleshed with
normal conformation to produce a grade A carcass dressed
Judging Laying Hens
Laying hens are evaluated on the ability to produce eggs
Things to consider– Present production– Past production– Rate of production
Judging Laying Hens
Present production– Large bright red comb– Softy waxy comb– Bright eyes
Judging Laying Hens
Past Production– Production indicated by yellow
pigment left in the body– The more eggs produced results in
less pigment– A soft pliable abdomen and moist
enlarged and bleached vent indicates that the hen is currently in production
Judging Laying Hens
Pigment bleaches beginning in:• vent• eye ring• ear lobe• beak starting at the base• front shanks• rear shanks• tops of toes• hock joint
Ready to Cook Broilers and Turkeys USDA grades A, B, & C
– determined by:• Confirmation• Exposed flesh on breast and other parts• Missing parts• Broken and dislocated joints
Ready to Cook Broilers and TurkeysFactor A B CExposed Flesh
Breast NoneElsewhere 1 ½ inch
Disjointed and broken bones
Missing Parts
1/3 flesh on
each part
No Limit
1 disjointed no broken
2 disjointed no broken
No Limit
Wing tip and tail
To the second wing
joint
What Grade is this?
Grade A
No Defects
B Grade
Back is cut out halfway between the base of the tail and the hip joints
What Grade is this?
C Grade
More than 1/3 of flesh exposed on
breast
What Grade is this?
B Grade
Parts of wing
removed beyond
the second joint
What Grade is this?
C Grade
Entire wing
removed
What Grade is this?
C Grade
Over 1/3 of the
drumstick flesh is
exposed
What Grade is this?
C Grade
Trimmed more than
halfway between base of tail and
hip joints
What Grade is this?
C grade
Protruding broken bone in wing tip
What Grade is this?
Grading Eggs
Interior quality determined by candling– AA, A, B or Reject– Bloody eggs are rejected
Exterior quality– A, B or Dirty– Any surface matter grades “dirty”
Grading Eggs
Interior quality (air cell size):AA- 1/8” (dime)A- 3/16” (nickel)B- Over 3/16” (quarter)
Recommended