Basic beef genetics

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