Group Title: Department of Animal Science research report - University of Florida Dept. of Animal Science ; no. AL-1975-7
Title: Use of visual appraisal with cow production and postweaning performance records for bull selection
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Permanent Link: http://ufdc.ufl.edu/UF00073074/00001
 Material Information
Title: Use of visual appraisal with cow production and postweaning performance records for bull selection
Series Title: Department of Animal Science research report
Physical Description: 3 p. : ; 28 cm.
Language: English
Creator: Wakeman, D. L ( Donald Lee ), 1929-
University of Florida -- Dept. of Animal Science
University of Florida -- Agricultural Experiment Station
Publisher: Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1975
 Subjects
Subject: Beef cattle -- Breeding -- Florida   ( lcsh )
Cattle -- Performance -- Florida   ( lcsh )
Bulls -- Performance -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: D.L. Wakeman.
General Note: Caption title.
General Note: "May, 1975."
Funding: Animal science research report (University of Florida. Dept. of Animal Science) ;
 Record Information
Bibliographic ID: UF00073074
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 80158970

Full Text

'4/q; Department of Animal Science Florida Agricultural
Research Report No. AL-1975-7 Experiment Station
S May, 1975 Gainesville, Florida

USE OF VISUAL APPRAISAL WITH COW PRODUCTION AND
POSTWEANING PERFORMANCE RECORDS FOR BULL SELECTION

D. L. Wakeman
Bull selection is an important task for ranchers to establish and continue
breeding programs. Since herd bulls contribute so much to immediate calf-crops
through male calves and to future calf-c replacement heifers, it is
imperative that the buyer us a proach based on all available
information. Selection of u 1 ne wit a definite goal in mind.
This goal should be to impr v Te production of th herd under the conditions
on their ranch. Selection for traits witb y heri ability estimates that will
improve the economic product on of # d' R5 the irst criteria that should
be considered. Not all bull buyers will select for e same traits since their
cow herds and production objectives will vary jla rates a market for several
different types of bulls with dif e~ n Oij dgtfi performance traits and
characteristics.

If possible, bulls should be selected from herds with production and per-
formance records established under the same kind of environment that exists in
the region where they will be used. Prospective buyers can make more accurate
selection decisions when an abundance of production and performance information
is available.

Cow production records provide a measure of the performance of the calves
up to weaning including the milking ability of the cow and the early growth
potential of the calf. Other information that is often included in production
records are weaning scores, adjusted weaning weights, fertility of the dam and
a record of calving ease. These records are for comparison of production traits
under the environmental conditions of that ranch. A change of environmental
conditions may influence the performance of these animals; however, it might be
expected that cows with superior production records would outperform cows with
poorer records under most environmental conditions. Cow fertility and preweaning
calf growth are two influential economic traits in establishing and maintaining
beef breeding herds. Most of the information in cow production records will
relate to these traits. Heritability estimates for these traits are listed in
Table 1. The higher the heritability estimate for a trait, the more rapid the
progress that can be obtained by selection for it. Genetic progress can be made
in a herd by selecting for traits with heritability estimates as low as .10-.20.

Performance records provide a measure of the performance of bulls and re-
placement heifers after weaning. These usually include measures for traits such
as 365-day weight, 18-month weight, 140- or 550-day postweaning test results,
average daily gain (ADG) to a given age and conformation scores. The herita-
bility estimates of these traits are also listed in Table 1. The heritability
estimates for weights at 365-days, 18 months and at maturity (4 to 5 years) are
high and rapid genetic progress for these traits can be obtained by selection
of bulls with superior performance records for these traits. Bulls that have
been fed on roughage or a low-energy ration will usually have lower weight gains than
bulls fed'high-energy rations; however, relative differences in growth rate can
be identified in both types of feeding programs if all bulls are provided free-
choice access to the same feed throughout the test period.

Presented at the 1975 Beef Cattle Short Course, University of Florida, Gainesville.









Body composition of the animals following a feed test should also be consid-
ered. An efficient measure of body composition can be obtained by feeding at
least ten offspring of a bull and obtaining carcass data when slaughtered at their
optimal slaughter age and weight. This information is usually available only on
established herd sires. Body composition estimates can also be made on bulls
following a feed test by use of the K-40 (radioactive potassium) method, sonascope
measurements and "eyeball" determinations of fat thickness. Combinations of these
methods provide the most useful information.

"Eyeball" evaluations should never be used to replace cow production and
postweaning performance records. Many cow production traits, such as milking and
mothering ability, cannot be evaluated by visual appraisal. "Eyeball" evaluations
should be used for such traits as structural soundness, temperament, masculinity,
testicular development, body frame size, breed characteristics, sheath soundness,
pigmentation and often for the amount and desirable types of muscling. The common
structural unsoundness conditions that should receive severe discrimination are
"post legs", curled or turned pasterns, broad-open-type shoulders, high and narrow
pelvis openings, buck knees, calf knees and extreme under-shot or over-shot jaws.
Physical traits that should receive mild discrimination, except in extreme con-
ditions, are sickle-hock conditions, cow-lock conditions, weak pasterns, toed-out
front legs and a wry nose condition. These traits affect the animal's performance
only when they are found in extremes and are often over exaggerated in visual eval-
uations.

We have several bulls with performance and production information available
to illustrate some of the problems encountered and decisions that must be made
when selecting bulls.


Table 1. Heritability Estimates for Beef Cattle.


Trait
Birth weight
Weaning weight
Weaning score
Average daily gain, feedlot
Efficiency food conversion
Average daily gain, pasture
12-month weight
18-month weight
Carcass grade
Rib-eye area
Retail cuts, percentage
Tenderness
Marbling
Temperament
Calving interval
Fertility
in good reproduction cattle
in poor reproduction cattle
Mothering ability
Milking ability (beef cattle)
I


Heritability
.40
.30
.32
.45-.50
.50
.35
.40-.50
.50-.60
.45
.45-.60
.40-.50
.60
.10
.35
.05-.10


(>.85)
(<.70)


.08
.20
.30
.25






PERFORMANCE RECORDS OF SALE BULLS


POSTWEAN DATA


WEANING DATA


Bull Age
Birth in
Date Days


010274

010774

011874

011974

,012974

020474

020674

021174

030874

030874

030974


461

456

445

444

434

428

426

421

396

396

395


Weight
4-8-75*


960

900

1040

960

970

910

960

1030

850

820

940


ADG


Wean Wean 205-
Index Wt. Day
Wt.


2.03

1.91

2.12

2.08

2.27

1.86

2.12

2.56

2.14

1.78

2.35


480

450

540

470

435

470

460

425

345

400

385


442

425

531

464

448

497

491

462

429

502

482


205-
Day
AAD wt.


508

425

531

464

470

522

491

485

493

577

555


Confor- Sire Dam


No. Accum-


matIon Code Herd Calves ulated
Score No. No. Weaned** Index


13

11

13

11

12

11

15

12

11

12

12


14

1809

6306

14

1809

14

1809

1809

14

14

1809


212

627

807

831

017

917

517

002

214

228

237


1/1

6/7

4/5

5/5

2/3

12/13

5/7

2/3

1/1

1/1

1/1


* 236 days after weaning
** Potential for number of calves weaned if bred to calve at two years old


This public document was promulgated
at an annual cost of $25.50 or 3U
per copy to present information on
livestock production.


Bull
Herd


403

409

437

439

459

463

465

470

483

484

485


DAM'S RECORD


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ANGUS


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