Beef Cattle Browsing
Editor: Dr. Stephen Hammack, Professor & Extension Beef Cattle Specialist Emeritus
April 2004
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.
HAS CHOICE BECOME EVEN CHOICER?
Up until the last year or so, carcass price for U. S. Choice has averaged about $7/cwt higher than for U. S. Select, or about $50 per carcass. Over the last year or so, that difference has averaged about $15/cwt, or over $100 per carcass. While that difference varies considerably over time, depending largely on the relative percentages of Choice and Select, it appears the market may be paying even more premium for higher-grading cattle. We’ll see if this trend continues.
ENERGY AND STARCH LEVELS FOR RECEIVING CALVES
Oklahoma researchers used 572 calves bought in four groups from north Texas, Arkansas, and southeastern Oklahoma auctions to study effects of two energy levels and two starch levels during the first 42 days after receiving. Group initial average weights were 416 lb, 497 lb, 381 lb, and 350 lb. The high-energy ration (72% TDN) had more alfalfa and corn and less cottonseed hulls than the low-energy (65% TDN). The high-starch ration (48% of energy from starch) had more corn and less corn distillers grains than low-starch (34% starch energy). Daily gain and feed efficiency did not differ among treatments. Energy level had no effect on sickness. High-starch calves had 9% higher sickness than low-starch (statistically significant at 0.11 level). (J. Animal Sci. 82.837)
IS CAB REALLY BETTER?
Oklahoma researchers compared Certified Angus Beef, U. S. Choice, and U. S. Select steaks from 150 carcasses, which ranged in Quality grade from Low Select to High Choice and in Yield Grade from 1.0 to 3.9. Based on mechanical shear force, CAB was slightly more tender with Choice being intermediate. Based on trained taste panel results, CAB and Choice had significantly higher scores for juiciness and flavor, but not for tenderness. CAB and Choice did not differ for any taste-panel characteristic. Even though the differences for juiciness and flavor between CAB/Choice and Select were statistically significant, that difference was only 0.24 units (on a scale from 1 to 8) for juiciness, and 0.11 units (scale from 1 to 4) for flavor. Also, the Select group had 20% more Yield Grade 1 and 2 than CAB, and 16% more 1 and 2 than Choice. (J. Animal Sci. 82:1437)
HEAT SYNCHRONIZATION – WHICH PROGRAM IS BEST?
Researchers at the A. I. organization Select Sires studied several combinations of melengesterol acetate (MGA), prostaglandin (PG), and gonadotropin-releasing hormone (GnRH) for synchronizing estrus in post-partum cows and virgin heifers. Four experiments were conducted in 11 herds. There was significant interaction between herd and treatment and between parity and treatment. In general, it was concluded that all three materials had similar utility in cows, except for poorer response from one procedure using a split feeding period of MGA. In heifers, a procedure using GnRH, short-term (6-day) MGA, and PG reduced estrus response and delayed interval to estrus. (J. Animal Sci. 82:867)
CAN BEEF TRAITS BE CHANGED BY GENETIC SELECTION?
The U. S. Meat Animal Research Center studied genetic influence on carcass and meat attributes, using data from over 4000 steers collected over a period of 20 years. Included were 22 breeds, representing a wide range of both Bos taurus and Bos indicus. Heritability of marbling (0.46) and percent retail product (cutability, 0.59) indicated these two traits could be easily changed over time by selection of breeding stock. Heritability of taste-panel tenderness was lower (0.26) but still high enough to result in change through genetic selection. However, heritability of flavor and juiciness was essentially zero (0.05 and 0.01, respectively), indicating little genetic variability for these traits, therefore little chance of change through genetic selection. (J. Animal Sci. 82:647)
NATIONAL ID TO BE REQUIRED?
Up to this point, the U. S. Animal Identification Plan has been just that, a plan that is strictly voluntary. However, Neil Hammerschmidt (USDA coordinator for animal ID) recently stated to the Animal Agriculture Alliance Stakeholders Summit that USDA plans to institute the program voluntarily at first, then make it mandatory. There had been speculation by many that something of this sort would happen. Looks like the speculators were right.