Herd Bull Selection, Evaluation, Pricing and Management

Cameron Co. Master Rancher Program

Joe C. Paschal

Livestock Specialist

Texas A&M AgriLife Extension

Corpus Christi, Texas

Breeds

Breed group Body size

Milk potential

Age at puberty

Hot climate adapted

Fleshing ability

Muscle expression

Cutability Marbling

British M M H-VH M H M L H

Continental beef

VH L L M M VH VH L

Continental dual purpose

H H M M M H H M

Bos indicus H M VL EH H M M L

American M-H M L-M VH H M L L-M

Functional Levels of Production of Major Breedtypes in Texas

(adapted from Hammack, 2003)

Cow breed or cross

Sire Breedtypes

British Bos indicus American Continental Heifer

British M

(XB)

R M M R

Bos indicus R R R

Bos indicus M R M R

American M R

(XB or PB)

M R

American cross

M M M

(No AXC dams)

R

Continental –British

M R M M R

Continental-Bos indicus

M R M R

Heifers S S S

Breedtype Combinations for Commercial Beef Herds(adapted from Hammack, 2003)

Selection Criteria• Structural correctness

• Beef character

• Adjusted weights

• Postweaning average daily gain

• Scrotal circumference

• Breeding soundness examination

• Bull gain test data

• Carcass data

• Maternal performance

• SELECT TRAITS THAT ARE ECONOMICALLY IMPORTANT TO YOU

Forequarter Structural Correctness

• Well structured shoulder

• Front legs at right angle (90o) from the shoulder through the point of the shoulder to the elbow

• A 120o angle from the elbow through the back of the pastern

• Front hooves slightly turned out (20o)

• Front legs parallel

Hindquarter Structural Correctness

• Slight slope from the hooks to pins

• A line drawn from the hook through the stifle should line up with the hock

• A right angle should be seen from the hook through the pin to the stifle

• A 120o angle should be seen from the stifle to the hock and down to the pastern

• The hind legs should be parallel and the hooves should be turned out slightly (20o)

Muscularity• Bulls should be thickest

through their middle hindquarters

• A strong, wide, flat back is an indicator of muscling

• Bulls with wide shoulders are not necessarily muscular

• The circumference of the upper forearm is a good indicator of muscling

Reproductive Evaluation

• Pass a Breeding Soundness Examination (BSE) annually

• Sheath should be above the A – B line (from the knees to the pasterns)

• The angle of the sheath should drop behind the front pasterns

• The opening of the prepuce should be tight

• Scrotal circumference should exceed 34 cm for yearlings

Scrotal Size• Scrotal size is highly

correlated with daily sperm production and can be measured repeatedly therefore it is an accurate measure of sperm production– Bulls with larger testicles

produce more semen and sire sons with larger testicles

– Bulls with larger testicles generally reach puberty at an earlier age and sire earlier maturing heifers and sons

Mating Ability

Performance Records

• All records should be adjusted for sex, age of calf and age of dam (if there is a maternal influence)

• Bulls should be compared within contemporary groups

• Expected progeny differences (EPD) and accuracy (ACC) values are refined forms of these records

Expected Progeny Difference

• Genetic prediction of how future progeny of an animal are expected to perform compared to progeny of other animals in that breed for a trait.

• Best measure of actual genetic merit.• Expressed in units of measure for the trait.• Can be positive or negative showing an increase

(+) or decrease (-) in the trait of interest.• Can be used to predict genetic merit for any trait.• Can change when additional information is added

to the data base making the EPD more accurate.

Creating and Using EPD

• Purebred cattle owners collect records (data) on their registered cattle and send the records to their breed association.

• The breed association sends the pedigree and the performance data to a genetic company for analysis.– Records of close relatives (parents, progeny) add more genetic

information than more distant relatives (sibs, grandparents).– Records of close relatives improve the accuracy of the EPD more

than distant relatives.– Adding genomic information improves the accuracy of the EPD

of young animals without progeny.

• Average EPD for a breed changes with additional information and an animals EPD can also change.

• Only current EPDs should be used for selection.

EPDs Require Accurate Records

• Purebred cattle breeders must collect accurate and timely records– Breeding date (artificial

insemination)

– Birth weight and date

– Weaning weight and date

– Yearling weight and date

– Scrotal circumference and date

– Carcass weights and measures (actual or ultrasound)

• Sire and dam must be accurately identified

• Calves grouped by sex, breed, and management group

• EPD can be used to estimate genetic value – Traits only in one sex (milk)

– Traits hard to measure (feed efficiency, tenderness)

– Traits later in life (carcass weight)

– Traits measured in dead animals (carcass quality)

EPD Traits• Traits

– Calving ease (direct and maternal)

– Gestation length– Birth weight– Weaning weight– Yearling weight– Carcass weight– Ribeye area– Marbling/Quality grade– Tenderness– Maternal ability– Heifer pregnancy– Scrotal circumference– Stayability– Docility

EPD Indexes• Maternal Indexes

– $Combined

– $Wean – selling at weaning

– $Maternal – replacement females

– $Energy – energy for maintenance

– API – All Purpose Index (Simmental)

– BMI$ - Baldy Maternal Index

– BII$ - Brahman Influence Index

– HerdBuilder – Red Angus

– $Cow – Gelbvieh

– Fertility Index – Beefmaster

– $Queen – Brahman

– Cow Calf - Santa Gertrudis

• Terminal Indexes – $Beef – traits for retained ownership

– $Fed – traits for feeding

– $Grid – marketing carcass

– TI - Terminal Index (Simmental)

– MTI – Limousin

– EPI and FPI – Efficiency and Feeder Profit Indexes (Gelbvieh)

– TSI (Charolais)

– GridMaster – Red Angus

– CHB$ - Certified Hereford Beef

– $T Beefmaster

– TI Terminal Index (Brangus)

– $BULL - Brahman

– BALANCED (Santa Gertrudis)

– Terminal (Santa Gertrudis)

Why Collect Genoytpes (DNA)?

• All breed associations require AI bulls and ET dams to have genotypes on file to ensure pedigree

• Semen, hair follicles, blood, or tissue can all be used

• Each association has their own preference

• Genoytpes can be used for parentage questions, genetic recessives and to improve the accuracy of EPD

• BUT phenotypes – records RULE!

What is Ultrasound?• Real time ultrasound uses high

frequency sound waves to “see” under the hide of a live animal

• The sound waves travel at different speeds through structures of different densities (hide, fat, muscle, or bone)

• Fat thickness, ribeye area, percent intramuscular fat (marbling score) and rump fat thickness can be accurately measured

• Can be combined with actual measurements for EPD

Relationship of Percent IMF to Quality Grade

Percent

IMF

Quality

Grade

Marbling Score

2.3-3.0 Select - Slight 0-49

3.1-3.9 Select + Slight 50-99

4.0-5.7 Choice - Small 0-99

5.8-7.6 Choice Modest 0-99

7.7-9.7 Choice + Moderate 0-99

9.9-12.1 Prime - Sl. Abundant 0-99

12.3 + Prime Abundant 0-99

Bull Management

Pricing Bulls

• Breed

• Color or color pattern

• Bloodlines

• Performance records

• Location

• Number offered at sales

• Private treaty

Young Bulls• Young bulls should be

developed slowly

• Some concern over feeding cottonseed

• Must acclimate them to other bulls

• Never turn out with older bulls

• Breed fewer cows

• Have poorer records but not necessarily poorer genetics

• COST LESS

Managing Beef Bulls

• Purchase early and acclimate

• Buy BSE tested bulls

• Watch them to make sure they are checking heat and breeding cows

• Supplement them if they are losing a lot of condition

• Watch for lameness or crippling