Beef Cattle Browsing – September 2014

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.


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)


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, the flecks of fat within muscle, is the primary determinant of official USDA Quality Grade. Marbling is officially evaluated in the ribeye between the 12th and 13th 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.


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)


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.)


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.)


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)


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