Beef Cattle Browsing – September 2008

Beef Cattle Browsing

Editor: Dr. Stephen Hammack, Professor & Extension Beef Cattle Specialist Emeritus

September 2008

This newsletter is published by Texas AgriLife Extension – Animal Science. Media, feel free to use this information as needed and cite Texas A&M University Beef Cattle Browsing Newsletter, Dr. Steve Hammack.

Under the mandatory Country of Origin Labeling that will go into effect the end of this month, producers can be responsible for certifying the origin of cattle that eventually wind up as retail product. The USDA has set out requirements for complying but has said they will not develop any documents to be used for this purpose. In response, a group of 70 representatives from the livestock, packing, and retail sectors met in late August to develop materials that would be suitable for complying with COOL. Those materials can be found at and other industry sites. Also, some entities such as local livestock marketing facilities may have developed their own in-house documents for sellers to sign.

The  U. S. Meat Animal Research Center at Clay Center, NB, studied selection for calving ease in four purebred and three composite groups. All of the cattle involved were of British and/or Continental breeding. The study was conducted over seven years, producing almost 9,000 calves from 586 sires. In the purebred groups, replacement males and females were selected to increase yearling weight and maternal effects on weaning weight. In the composite groups, replacements were selected to stabilize yearling and maternal weaning weight effects. Within each of the seven breed-type groups, two lines were formed, called control (CO) and calving ease (CE). In all CO lines, birth weight was kept in proportion to yearling weight in order to stabilize calving difficulty. But in the CE lines, replacements were selected for calving ease, based on subjective calving difficulty score (1=no assistance, 7=cesarean).

Genetic Effects: By the end of the study, 1.56 generations of selection had occurred. In the CE line, estimated breeding value (EBV) for calving ease had decreased by 1.06 calving-difficulty scores and was accompanied by decreased EBV of 7.7 lb for birth weight. There were no significant differences between the lines in change of EBV for any other traits. In the purebreds, EBV for yearling weight increased by an average of 50 lb.

Phenotypic Effects: Over seven years, CE lines averaged 3.0 days earlier calving, 1.8 days shorter gestation, 6.6 lb lighter birth weight, and 0.8 lower calving-difficulty score with 19.8% fewer assisted births in two-year-old heifers. (There were no differences in assisted births between CE and CO in three-year-old and older cows). CE averaged 7.0 lb higher preweaning gain so, coupled with lower average birth weight of 6.6 lb, weaning weight did not differ from CO and yearling weight also did not differ. As yearlings, CE heifers averaged about 0.3 inches shorter at the hip. Pelvic areas did not differ between CE and CO.

The authors concluded that genetic selection for calving ease EBV can be effective in reducing two-year-old heifer calving difficulty and calving assistance while maintaining or increasing yearling weight. (J. Animal Sci. 86:2093 and 2103)

Research has shown that high-protein supplements can generally be used effectively without feeding every day. However, common high-energy supplements (fed at higher rates) are usually not as effective unless fed every day and may even depress performance. University of Florida researchers wanted to know the effects of feeding  fibrous byproduct supplements, specifically in Brahman-cross cattle. They supplemented 56 Brahman x Angus heifers either every day (S7) or three times a week (S3) at the daily rate of 1.0% body weight (so S3 got about 2.3% of body weight, on Monday, Wednesday and Friday). The supplement was mostly wheat mids (67%) and soy hulls (27%). Available forage had about 8% CP and 54% TDN. The S7 heifers gained significantly higher and more of them reached puberty and became pregnant. The authors concluded that supplementing these byproducts on low-quality forages was more effective when fed daily rather than three times a week. (J. Animal Sci. 86:2296)

It’s declining, according to the USDA – Economic Research Service. The 1994 Nutrition Labeling and Education Act of Congress required on packaged and processed foods a standardized nutrition label, to include a Nutrition Facts panel, ingredient list, and information on calories, fat, cholesterol, and sodium. Compared to 1995-96, consumer use of this information in 2005-06 declined except for sugars, which remained steady, and fiber, which increased slightly and was most apparent in people over 30 years of age. Decline in use was highest in the 20-29 year-old age group, those with no formal education beyond high school, and primarily Spanish speakers. In the 2005-06 survey, health-claims information was least used (43%) and total fat was most used (70%). It will be interesting to see what use consumers make of labels mandated by COOL.  (

USDA-ARS genomics researchers at the Subtropical Agricultural Research Center in Brooksville, FL, have identified molecular markers linked to a gene for short, slick hair. They determined the gene is responsible for slick hair in at least two heat-tolerant breeds, Senepol and Romosinuano. The researchers speculate that introduction of the gene could improve heat tolerance in breeds such as Holstein and Angus. They cite Florida studies showing that slick-haired cattle have internal temperatures in summer about 1 degree F. lower than cattle with normal coats. (USDA-ARS Newsletter downloaded 8/15/08)

Nobody likes to get up in the middle of the night to check a set of heifers about to calve. There has been some indication that feeding in the evening can affect when calving occurs. Kansas State University and Oregon Stat University researchers collaborated to study this topic. For 15 years, spring-calving Hereford and Charolais cows located in western Idaho were full-fed alfalfa hay or oat silage every day between 6 am and 8 am beginning two months before calving began. For 5 years, Hereford x Angus and Angus x Brahman spring-calving cows located in western Kansas were full fed sorghum hay every day between 4 pm and 6 pm beginning two weeks before calving began. Distribution of calving in the morning-fed herd was very uniform. From 15 to 18 percent of cows calved during each four-hour period of the day. But in the afternoon-fed herd, approximately 85% of calvings occurred from 6 am to 6 pm. Also, in this herd there was less variation over years in time of calving for a particular cow. In both herds, there was a tendency for daughters to give birth at a similar time of day that her dam gave birth. The authors concluded that feeding time affects calving time. (Prof. Anim. Sci. 24:247)

Most of the value of slaughter cattle comes from beef. But there are other things that have value. These are grouped into “hide and offal”, which includes hides (which have the largest value), tallow, meat-and-bone meal, blood meal, and non-carcass variety meats such as livers, tongues, etc. Currently, total hide and offal value is $11-12/cwt live. Over the last two years, hide and offal value has increased about $54/head. The biggest contributor to that increase is tallow, which can be refined into fuel, followed by livers and then meat-and-bone meal. (USDA-AMS) 

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