Beef Cattle Browsing – January 2013

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.

According to the tv, internet, newspapers, magazines and other “usually reliable” sources, it comes from cows. However, USDA researchers at the U. S. Salinity Laboratory in Riverside, California, report “People blame cows for so many things” but “pathogens that end up in local waterways are more often carried there via runoff from urban areas, not from animal production facilities.” But it’s much easier to blame “factory farming” for all problems than to address other sources, which may require more changes in how the public operates than how agriculture does. ( downloaded 12/7/2012)

Mixed common bermudagrass-dallisgrass pastures were overseeded with annual ryegrass. Pastures were continuously stocked for three years with spring-calving Brangus cows and calves at 2 acres/cow (CL), 1.6 acres/cow (CM), or 1.1 acres/cow (CH) or rotational stocked at the high rate of 1.1 acres/cow (RH). Pastures for the rotation treatment were divided into 8 paddocks. Compared to the 30-year-average, annual precipitation was about average for the first year of the study, below average for the second year, and above average for the third year.

As expected, forage mass increased as stocking rate decreased. Forage quality was higher for CH in early spring and summer. Reproductive performance was similar except for RH being lower. As stocking rate increased, weaning weight decreased but pounds of calf weaned per acre increased. Weaning weight and weight per acre were similar for continuous or rotation stocking at the high rate. In a separate analysis, economics favored CM and CH, so the authors concluded that, under conditions of this study, moderate to high continuous stocking was indicated. (Prof. Anim. Sci. 28:417; Louisiana St. Univ., Oklahoma St. Univ.)

A total of 582 suckled beef cows at 8 locations in 2 regions were synchronized using the CO-Synch + CIDR protocol followed by timed artificial insemination. At the same locations, 615 cows were exposed to natural service without synchronization to serve as controls. Cows were of British, Continental, or British-Continental background. Both groups were exposed to bulls, 12 hours after the last cow from the treatment group had been AIed, for periods of 42 to 69 days depending on the location.

Calf crop percentage (calves weaned/cow exposed to breeding) averaged 84% for the AIed group and 78% for controls. Average calf weaning weight was 38 lb heavier for the AIed group. (The authors presumed this was at least partly due to higher genetics for weaning weight for the AI sires, but no data were available.) Costs for the AIed group were lower due to fewer bulls required for cleanup, compared to bulls needed for the control group. Calves were valued at $121/cwt. Overall, the AIed group returned $49.14 more per exposed cow. (J. Animal Sci. 90:4055; Univ. of Minnesota, Mississippi St. Univ., Univ. of Florida, North Dakota St. Univ.)

After five years of study, the USDA-Agricultural Marketing Service has implemented a program where tenderness of beef can now be legally claimed, and marketed. The program uses third-party verification of testing procedures under the American Society for Testing and Materials. Samples must be prepared and cooked according to protocol of the American Meat Science Association. Verification can be obtained for “tender” (Warner-Bratzler shear force value no higher than 9.7 lb) or “very tender” (no higher than 8.6 lb). Time will tell if this program will be implemented by meat processors and, if so, what effects might result back down the production cycle. (

Most finished cattle receive a growth implant. A study was designed to assess effects of delayed growth implanting in high-risk calves. A total of 1601calves averaging 602 lb was procured in several southeastern auction barns and shipped to a central Kansas feedyard. Calves were implanted with Revalor-XS either during processing at arrival or 45 days later. Delayed implanting tended to reduce sickness and significantly reduced early harvest due to nonresponsive chronic respiratory treatment. But there was no significant difference in retreatment, death, lung lesions, pleural adhesions, ADG, feed conversion, hot carcass weight, USDA Quality or Yield Grade, cost of gain, or total carcass value . The authors concluded there appeared to be no advantage to handling high-risk cattle a second time to delay implanting. (J. Animal Sci. 90:4037; Kansas St. Univ.)

Zilpaterol hydrochloride (Zilmax®, ZH) has generally been shown to improve feedlot performance and retail yield, but often with some reduction in meat tenderness. Calcium chloride injection has been shown to improve tenderness in some cases. USDA Select strip loins were obtained from cattle fed ZH and from untreated controls.  One-half of each group was injected with calcium chloride 72 hours post mortem. At 7 days post mortem steaks were cut, vacuum packaged, and aged for another 0, 7, 14, or 21 days, at which times Warner-Bratzler shear force tests were conducted.

At each period, ZH steaks had lower tenderness and injected steaks had higher tenderness. Tenderness was improved for both as aging increased. The authors concluded that injecting calcium chloride reduced tenderness variation in ZH-fed cattle as it does in non ZH-fed. (J. Animal Sci. 90:3584; Texas Tech Univ., Merck Animal Health)

Mandatory country of origin labeling (COOL) has been in effect since March, 2009. Proponents of COOL had maintained that consumers had a right to know country of origin and that labeling would increase price paid for US product. Opponents maintained that the program would increase cost to the industry without increasing price enough to offset cost. A study was designed to assess the impact of MCOOL on consumer behavior. Important findings were:

  • demand has not increased for meat covered under COOL,
  • typical consumers are unaware of COOL and do not look for labels, and
  • consumers say they value information on origin, but don’t pay extra for it.

The authors concluded that an economic loss has accrued to the industry as a result of COOL. NOTE: the World Trade Organization has recently ruled COOL to be unfair to Canada and Mexico; the U. S. government is currently evaluating whether to change COOL in order to comply, stop the program, or take no action and accept what penalties might result. (; Kansas State University)

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