Basic Beef Genetics
Tom Gallagher (CCE Albany)Meghan Filbert (CCE Delaware)
Phil Trowbridge (Trowbridge Angus)
Selecting Your Next Bull
Phil Trowbridge, Trowbridge Angus Farms
Importance of bull decisions• A bull in natural service
normally sires 20 to 40 calves each year.
• Herd improvement, for the most part, comes from the sires chosen to produce each calf crop.
• Ask yourself: What do I want the bull to do other than breed the cows?
• Analyze the market –Determine what type of animal is profitable to produce. What do you want the animal to do other than breed cows?
• Decide what genetics are needed to improve your cow herd.
What first?
• Physical evaluation – is the animal structurally sound? In healthy condition? Show signs of potential problems?
• Records – is there performance information associated with the bull? What can you expect from future progeny?
• Strategy – does the animal meet your specific herd needs and goals?
Bull selection criteria
Structural soundness
• Starts from the ground up• Bull needs to be sound to
avoid injury and last many years
• Structure is heritable – offspring will have similar traits
• Scrotal size affects:– The serving capacity of
the bull and hence the number of times the cow is served.
– The number of normal sperm in each service, which depends on the size and condition of the bull's testicles.
Structural soundness
Phenotype + genotype
Understanding basic structure and physical attributes are important, but studying
genetic and performance data is becoming increasingly important in the beef industry.
Analyzing genetics
• Types of traits– simply inherited:
differences among animals are due to one or two genes (i.e. hide color).
– performance traits: differences are due to a number of genes (i.e. birth weight, marbling).
• Performance is a combination of genetics and environment.
• Expected Progeny Differences (EPDs)– Derived from performance records, pedigree
information and, where available, genomic data. – 18 available EPDs available for sire selection tools.
Using technology
Expected Progeny Difference
• An EPD is the expected difference in future progeny performance of one individual compared to another.
• Used to compare all cattle within a breed.• EPD does not equal actual performance.• Considering EPDs can help you make the best
possible bull decisions for your operation.
Example: Birth Weight
• On average, Bull A’s calves are expected to weigh 5 pounds less than Bull B’s.
BW EPD
Bull A -1.0
Bull B 4.0
Example: Weaning Weight• Assumptions
– 67 Commercial Cows & 2 Herd Bulls
– 90% Calf Crop average (per cow exposed)
– Sell all calves at weaning– Feeder Calf Prices @
$1.40/pound– Use Bulls for 5 years– Bull 1 has weaning weight
EPD of +40 lb– Bull 2 has weaning weight
EPD of +20 lb
Bull 1
Bull 2
BW EPD, lb +3
WW EPD, lb +40
Milk EPD, lb +16
YW EPD, lb +80
Bull 1
BW EPD, lb +3
WW EPD, lb +20
Milk EPD, lb +16
YW EPD, lb +80
Bull 2
Bull 2Bull 1
Projected GrossValue Difference
30 calves at 550#
5 years$1.40/lb
$4,200.00
$115,500
30 calves at 570#
$119,700
Before buying a bull
• Think about specific herd needs• Study performance data and EPDs• Examine physical correctness• Be confident in the genetics you’re
purchasing
Questions?
• Resources for more information:– trowbridgeangusfarms.com– angus.org
Heterability
Heterosis
Crossbreeding
• Why crossbreed? – Heretosis is free money – We can design cattle to fit any environment – To use average breed effects – To target specific beef markets
Designing a crossbreeding system
• Two breed rotation • Three breed rotation
Criteria for Selection
• Market– Grass fed genetics – Devon’s– Replacement heifers– Feed resources – Management resources – Farm environment
• Hills vs. flat land. Simmentals don’t like hills