- Beef Cattle Browsing
Editor: Dr. Stephen Hammack, Professor & Extension Beef Cattle Specialist Emeritus
Beef Cattle Browsing is
an electronic newsletter published by Texas A&M AgriLife Extension,
Department of Animal Science at Texas A&M University. This
newsletter is a free service and is available to anyone interested in
beef cattle. Media, feel free to use
this information as needed and cite Texas A&M University Beef
Cattle Browsing Newsletter, Dr. Steve Hammack.
CONSUMER PERCEPTIONS OF FOOD TECHNOLOGY
A recent survey was conducted to evaluate consumer perceptions of
food technology. Some of the interesting findings regarding labeling of
food were:
- 74% of consumers could not think of additional information they’d like on labels,
- 8% wanted more information on nutrition,
- 5% wanted more information on ingredients,
- 4% wanted more information on biotechnology or related subjects,
- 63% supported current labeling of biotechnology production only if
nutritional content is significantly changed or there is a potential
safety concern such as an allergen,
- 19% (up from 14% in a 2012 survey) disagree that current biotechnology labeling is sufficient.
On the topic of food biotechnology perceptions:
- 71% said they know something about plant biotechnology,
- 28 % had favorable perceptions toward plant biotechnology,
- 28% (up from 20% in 2012) had unfavorable perceptions,
- 43% were neutral or did not know enough to comment,
- more aged 18-34 had favorable perceptions than those over 34 years of age.
Regarding how biotechnology should be used in food production:
- 72% said to increase healthful fat content (such as Omega-3 fatty acids),
- 69% said to reduce potential for carcinogens,
- 69% said to protect from insect damage and reduce use of pesticides,
- 67% said to enhance nutrition,
- 67% said to eliminate trans-fat content.
As to perceptions of modern agriculture, responses were:
- 74% agreed that farming with modern tools and equipment can be sustainable,
- 72% agreed modern farming can produce high quality and nutritious food,
- 68% agreed modern farming produces safe food,
- 52% agreed that modern farming is primarily family operated.
“Sustainability” received the following responses:
- 57% had read or heard about sustainability related to food production,
- 66% said it is important to produce food sustainably,
- 26% (down from 33% in 2012) would spend more for food produced sustainably.
(Food Insight of 5/28/14, International Food Information Council Foundation)
EFFECT OF TRACE MINERAL INJECTIONS ON PRE-WEANED AND POST-WEANED CALVES
One-half of a group of 150 Brangus-crossbred calves were injected at
100 and 200 days of age with 1 ml of a product containing 60, 10, 15,
and 5 mg/ml of zinc, manganese, copper, and selenium, respectively. The
other one-half were injected at the same times with saline solution. All
calves were weighed on days 100, 150, 200, and 250 when weaned. Liver
biopsies were taken from 12 calves per treatment on days 150, 200, and
250. Trace-mineral injections had no effect on ADG but did increase
concentration of copper and selenium in the liver.
In a second study, one-half of a group of 34 weaned heifers was
weighed and injected with 2.5 ml of the product described above on day
0, 51, and 127. The other half was weighed and injected with saline
solution at the same times. On day 177 heifers were weighed and liver
samples taken. ADG and selenium concentrations were significantly higher
for the group receiving trace-mineral injections.
(J. Animal Sci. 92:2630; Univ. of Florida)
MARBLING – JUST A LITTLE CAN MEAN A LOT
Marbling, the flecks of fat within muscle, is the primary determinant
of official USDA Quality Grade. Marbling is officially evaluated in the
ribeye between the 12
th and 13
th ribs, i. e., where a carcass is separated into forequarter and hindquarter.
Slight marbling is the minimum required for USDA Select and Small
marbling is required for USDA Choice. As can be seen above, just a few
flecks divide those two grades, but that can mean a lot of money. Over
the last few years the average spread between Choice and Select is about
$8-9/cwt carcass, but has ranged from $0-20/cwt. Modest marbling gets a
carcass into upper 2/3 Choice, the minimum required for most branded
high-quality programs such as Certified Angus Beef. The premium for CAB
over Choice currently is about $4/cwt carcass. Slightly Abundant
marbling and higher results in a grade of USDA Prime. That premium
currently is about $20/cwt over CAB. However, only 3-4% of fed beef
grades Prime.
How is marbling determined? Until recently it was done exclusively by
an official grader’s eyeball. Now, grading is increasingly done by
instrument, subject to adjustment by a grader. Properly calibrated
instruments should result in the most accurate and repeatable
evaluation. Regardless, higher marbling usually means higher value. How
much higher depends on the value spreads, and those still depend largely
on supply and demand.
AN ALTERNATIVE PROGRAM FOR SYNCHRONIZING HEAT ?
A common program for synchronizing heat for artificial insemination
is the 5-day CO-Synch + controlled internal drug release (CIDR)
protocol. The standard 5-day protocol includes an initial administration
of gonadotrophin-releasing hormone (GnRH) at insertion of an
intravaginal progesterone releasing device (CIDR) followed 5 days later
by 2 doses of prostaglandin (PGF2α), given approximately 8 hours apart,
and CIDR removal and timed artificial insemination (TAI) with a second
GnRH 72 h after PGF2α. A study was designed to evaluate the necessity of
the first administration of GnRH and of two PGF2α doses rather than
one. The study involved four locations and 823 Angus X Simmental, Angus X
Hereford, Charolais, or Angus yearling heifers:
At CIDR insertion, one-half of all heifers received GnRH and one-half
did not. At CIDR removal, all heifers received PGF2α. All heifers were
TAIed and all received GnRH 72 hours after PGF2α. Pregnancy was
diagnosed at 32 and 38 days after TAI.
At CIDR withdrawal, presence of a new corpus luteum was significantly
higher in the group receiving GnRH twice. However, there was no
significant difference in pregnancy rate to TAI between heifers
receiving GnRH twice (50.5%) or once (54.9%). The authors concluded that
omitting the initial GnRH administration did not influence pregnancy
rate and that only one dose of PGF2α was effective.
(J. Animal Sci. 92:4198; Ohio St. Univ., Univ. of Minnesota, Univ. of Wyoming)
EFFECT OF TYPE OF BERMUDAGRASS ON FORAGE CHARACTERISTICS AND ANIMAL PERFORMANCE
Alicia, Jiggs, and Tifton-85 bermudagrasses were evaluated over four
consecutive years. Weaned, 9-month old 3/8 Gelbvieh, 3/8 Red Angus, 1/4
Brahman steers averaging 554 lb initially were grazed for an average of
112 days from June to September. Before grazing started, hay was cut and
pastures were fertilized with 40 lb N/acre. Forage samples were taken
when grazing started (day 0) and on days 28, 56, 84, and 112. A
free-choice mineral-vitamin mix (containing 12% Ca, 6% P, 10% NaCl,
trace minerals, and 2000,000 units Vit. A) was provided throughout the
grazing period.
As expected, percent crude protein and digestibility declined during
the summer grazing period. Alicia had lower digestibility than both
Jiggs and Tifton-85, resulting in significantly better performance on
Tifton-85 (1.21 lb ADG) and Jiggs (1.12 lb ADG) than Alicia (0.79 lb
ADG).
(J. Animal Sci. 92:1228; Louisiana St. Univ., Mississippi St. Univ.)
ESTIMATES OF TEMPERAMENT IN BRAHMAN AND BRAHMAN-CROSS
Over a 10-year period, 1209 Brahman and Hereford X Brahman calves
weaned at average of 186 days of age were evaluated for temperament.
Temperament was evaluated as 1) chute velocity, time taken to travel 6
feet from squeeze-chute release, 2) pen score, a subjective estimate of
“willingness to be approached by a human” where 1=nonaggressive to
5=very aggressive, and 3) temperament score, a combination of chute
velocity and pen score. Evaluation was done 28 days before weaning, at
weaning, 28 days after weaning, 56 days after weaning, and yearling.
Heritability was 0.27 for exit velocity, 0.49 for pen score, and 0.43
for combined temperament score. For all three evaluations of
temperament, measures were highest (less desirable) 28 days after
weaning. Pen score tended to be lower as dam age increased. Exit
velocity tended to increase as age at weaning increased. Pure Brahman
had statistically significantly higher pen scores than Hereford X
Brahman (2.91 vs. 2.49). However, since these averages are both in the
middle to high range of the slightly aggressive #2 category they may not
indicate important practical differences in behavior. Also, exit
velocity and combined temperament scores did not significantly differ
for the two genetic types.
(J. Animal Sci. 92:3082; Texas A&M Univ., Mississippi St. Univ.)
HOW FAST SHOULD HEIFERS BE DEVELOPED ?
Over two years, spring-born, weaned Angus heifers initially averaging
557 lb were developed for 202 days on a ration of grass-alfalfa hay
with some barley supplement. Heifers were fed to reach either 55%
(moderate gain, MG) or 62% (high gain, HG) of anticipated mature weight
of 1400 lb. The higher rate of gain was accomplished by feeding 28% more
digestible energy during the development period.
Development cost was significantly lower for MG ($58/head or 23%
less). At the end of the development period, HG weighed significantly
more than MG (872 lb vs. 778 lb) and were significantly higher in BIF
Frame Score, rib and rump fat cover, and internal pelvic area. At the
end of development in June, all heifers were placed on the same pasture
and breeding commenced. At start of breeding, significantly more HG were
cycling than MG (52% vs. 20%). MG gained significantly more than HG
during summer grazing (1.83lb/day vs. 1.55 lb/day) but by pregnancy
check in October HG were still significantly heavier (1054 lb vs. 990
lb) and higher in Body Condition Score (2.8 vs. 2.6 on 1-5 scale).
Pregnancy rate did not significantly differ, (88% for HG and 86% for
MG).
The study was continued for re-breeding as 2-yr-olds and 3-yr-olds.
As 2-yr-olds, HG continued to be significantly heavier just before
calving but this was not the case for 3-yr-olds. There was no
significant difference in first- or second-calf birth date, % calved in
first 21 days, birth weight, calving difficulty, weaning weight, cow
BCS, or rebreeding %. As has been found in other recent research,
development to first breeding of approximately 55-57% of anticipated
mature weight is more economical and results in no reduction in
performance, if nutrition is adequate during breeding.
(J. Animal Sci. 92:3116; Univ.of Saskatchewan, Univ. of Nebraska)