Effect
of Breed of Sire on Performance and Carcass
Characteristics of Beef Cattle
Jon Schoonmaker
and Vern Anderson
NDSU
Carrington Research Extension Center
Introduction
Worldwide,
there are more than 250 breeds of beef cattle. Over 60 of these breeds are
present in the United States and approximately 20 constitute a majority of the
genetics utilized in the U.S. for commercial beef production. The breed, or
combination of breeds used in a breeding program have a significant impact on
the efficiency and profitability of the beef enterprise. Breed influences
mature size, reproductive efficiency, and maternal ability of the cow, as well
as growth rate and carcass characteristics of calves. Nutritional requirements
and production costs are also related to breed. Therefore selecting appropriate
breeds to be used in a breeding program is an important decision for beef
cattle producers.
In
the past 25 years, considerable research has been conducted to characterize and
compare the major beef breeds in the U.S. The most comprehensive studies have
been conducted at the U.S. Meat Animal Research Center in Clay Center, NE.
Since 1970, over 30 breeds have been evaluated in a common environment and
management system for various performance traits (Cundiff
et al., 2004). The report presented here describes breed differences seen on a
much smaller population of animals located at the Carrington Research Extension
Center.
Procedures
Five
sire breeds have been used at the Carrington Research Extension center dating
back to 1987. Ten Hereford bulls and five Tarentaise bulls were used from 1987
to 1991, 24 Red Angus bulls were used from 1987 to 2004, 15 Limousin bulls were
used from 1992 to 2001, and three South Devon bulls were used from 1998 to
2004. Sires were procured from area breeders and natural matings
allowed for 45 to 50 days (from early June to mid July). Cows were bred to a
different breed sire to maximize the positive traits of the breeds used in the
cross. Cows calved from late February through early May. Cows were fed in open drylot pens with
fenceline bunk feeding throughout the year. Cows were used in research trials evaluating
feeding and management strategies at various times of the year. When not on a trial, cows were fed a least-cost
ration consisting of co-product feeds available in the region.
All calves were weighed, and
bull calves castrated within 48 hours of birth. Calves were weaned at approximately 170 days
of age, and weights were adjusted to a constant age of 205 days. Heifers were retained, but were not used in
research trials, thus growth data was not collected and little information is
available on heifer calf performance. Steers were also retained and were randomly
allotted, along with purchased calves, to various feedlot trial treatments. Steers were implanted and fed in open drylot
pens. Steers were fed a growing ration
for approximately three months with high grain finishing diets offered until
marketing in April. Cattle were marketed
and slaughtered at various packing plants. Carcass data was collected only in years when
the research trial objectives were specifically linked to meat quality. Research protocols regarding animal care
followed guidelines recommended in the Guide for the Care and Use of
Agricultural Animals in Agricultural Research and Teaching (FASS, 1998).
Data
were pooled across years and subjected to a one-way analysis of variance as a
completely randomized design using the GLM procedures of SAS (Version 8.0; SAS
Inst. Inc., Cary, NC). Planned pair-wise
comparisons (least significant difference) were used to separate treatment
least square means when the F-test was significant (P < 0.05). The model included effects due to breed of
sire, and individual animal was the experimental unit.
Results and Discussion
Birth weight (781 steers and
800 heifers), weaning weight (539 steers), slaughter weight (444 steers), and
carcass information (284 steers) for the various breed groups is summarized in
Table 1. Limousin-sired bull and heifer
calves were the heaviest (P < 0.01) at birth, whereas Hereford-sired calves
were the lightest at birth; Red Angus-, South Devon-, and Tarentaise-sired
bulls and heifers had birth weights intermediate to Limousin and Hereford.
Tarentaise-sired calves were the heaviest (P < 0.01) at weaning, followed by
Red Angus- and Limousin-sired calves; South Devon- and Hereford- sired calves
were the lightest at weaning. Limousin-sired calves were the heaviest (P <
0.01) at slaughter, dressed the highest, and produced the heaviest carcasses.
Red Angus-, South Devon-, Tarentaise-, and Hereford-sired calves ranked second,
third, fourth, and fifth, respectively, for slaughter weight, hot carcass
weight, and dressing percentage. Tarentaise- and Red Angus-sired calves
produced the best marbled carcasses (P < 0.01); Hereford-, South Devon-, and
Limousin-sired calves produced the least marbled carcasses. Limousin-sired calves produced carcasses with
the largest rib-eye area (P < 0.01) followed by South Devon-sired calves. Red Angus- and Tarentaise- sired calves
produced carcasses with the third largest rib-eye area; Hereford-sired calves
produced carcasses with the smallest rib-eye area. Hereford-sired calves had the lowest percent
KPH (P < 0.01); Limousin-, Red Angus-, and South Devon-sired calves had the
greatest percent KPH. Tarentaise-sired calves had an intermediate amount of
percent KPH . Limousin-sired calves produced carcasses
that were the leanest at slaughter (P < 0.01) as evidenced by a low fat
thickness and low yield grade. Red
Angus-sired calves produced carcasses that were the fattest at slaughter. South Devon-, Tarentaise-, and Hereford-sired
calves produced carcasses that were intermediate in fat level.

Red Angus,
There are several criteria
that should be taken into consideration when making breed selection decisions:
production system, management ability, market demands, quantity and quality of
feedstuffs available, climate, breed complementarity,
and cost and availability of purebred seedstock. The breeds chosen should produce calves that
are appropriate for their end use and optimize producer profitability. Cow-calf producers interested in raising
replacement heifers may emphasize maternal traits such as milk production,
mothering ability, calving ease, and small mature size. Producers selling weaned calves may want to
use breeds that increase growth rate and weaning weights. Producers interested in retaining ownership of
their cattle through slaughter may focus on breeds that increase muscle mass or
breeds that improve marbling.
No one breed excels in all
traits that are important for beef production.
Crossbreeding systems that exploit heterosis and complementarity
and match genetic potential with market targets, feed resources and climates
provide the most effective means of breeding for production efficiency.
References
Cundiff, L. V., T. L. Wheeler, K. E. Gregory, S. D. Shackelford, M. Koohmaraie, R. M. Thallman, G. D. Snowder, and L. D. Van Vleck. Preliminary results from cycle VII of the cattle germplasm evaluation program at the Roman L. Hruska U. S. Meat Animal Research Center. 2004. Available on the internet at: http://www.marc.usda.gov/cattle/gpe/GPE22.pdf