Beef Cattle Browsing – November 2012

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.

 

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

 

 

NEW TEXAS ID BEGINS JANUARY 1
Beginning January 1, 2013, by virtue of a Texas Animal Health Commission ruling, all adult cattle in Texas must have an approved form of permanent identification in place at any change of ownership. This includes sexually intact beef cattle 18 months older and above, and Mexican-origin event cattle. Not included are nursing calves, steers, spayed heifers, bulls, heifers under 18 months (unless they are about to calve), and cattle moved directly to slaughter. Forms of identification currently approved by TAHC for this purpose are:

  • USDA alphanumeric National Uniform Eartagging System (NUES) silver metal tags
  • USDA brucellosis calfhood vaccination tags (either USDA orange RFID or metal)
  • Dairy Herd Improvement Association (DHIA) tags with 9-digit American number
  • Official breed association registration tattoo (unique to the individual animal)
  • Official breed association registration fire or freeze brand (unique to the animal)
  • USDA approved 15-digit Animal Identification Number (AIN) tags including:
    • 900-series RFID tags if traceable to herd owner
    • USA prefix RFID tags
    • 840-prefix RFID tags (if premises location is registered)
    • 840-prefix non-RFID tags (if premises location is registered)
  • Cattle-style clip, flap, or button tag (if owner and individual animal is identified).

Tattoos and brands that are not part of breed association registration procedures are not approved forms of ID. A database of official ID numbers assigned will be maintained by TAHC, but there will be no tracking required of individual changes of ownership.

For those preferring to use USDA metal tags, TAHC will provide free tags and pliers. They may be obtained from local TAHC field staff or USDA-APHIS Veterinary Services representatives. Some interested veterinary practitioners will also have tags available. In addition, tags and pliers will be available from most Texas A&M AgriLife County Extension offices. For more information contact Texas Animal Health Commission at (512) 719-0710 or www.tahc.state.tx.us.

EFFECT OF ESTABLISHMENT METHOD AND STOCKING RATE ON WHEAT PASTURE PERFORMANCE
Over four years, wheat pastures were established by the conventional method of seed sown into prepared bed, reduced tillage by single-pass with light disk followed by broadcasting, or no-till direct seeding into unprepared stubble from previous-year graze out. Continental X British steers initially averaging 530 lb were placed on pastures of all establishment methods stocked at ¾, 1, or 1½ head per acre for fall grazing from early November to early March. All groups were then commingled for spring graze out, ending mid-April to mid-May.

Establishment method did not significantly affect forage mass or nutrient composition. Overall fall-spring ADG was lower for conventional establishment than for reduced tillage or no-till. During the fall period, ADG decreased but grazing days/head and gain/acre increased as stocking rate increased. In the spring period, animal performance of the fall-stocked rates did not significantly differ. Over the complete fall-spring period, grazing days/acre was greatest for the high fall stocking rate and lowest for the low fall stocking rate; total weight gain/acre was greatest for the high fall stocking rate and lowest for the intermediate fall stocking rate. (J. Animal Sci. 90:3286; Univ. of Arkansas)

RED ANGUS INCORPORATE GENOMIC DATA INTO EPD
Add the American Red Angus Association to the list of breed associations now incorporating DNA information into their genetic evaluation program. The primary benefit of doing this is to increase EPD accuracy of young animals and others without progeny data. In addition, Red Angus and Simmental have merged their programs such that EPDs for the two breeds are now directly comparable without applying conversion factors. (http://redangus.org/genetics/)

EFFECT OF SEXED VS. CONVENTIONAL SEMEN
A group of 500 heifers was synchronized and artificially inseminated with either sexed or conventional unsexed semen. Those heifers exhibiting estrus were AIed 18 to 24 hours after detection and remaining heifers were subsequently inseminated together. Pregnancy was determined 55 to 58 days after insemination. Conventional semen resulted in significantly higher pregnancy rate (58.4% vs. 41.0%). Also, more heifers detected in estrus were pregnant (55.9%) compared to those time-inseminated (24.0%). Based on these findings, use of sexed semen should allow for some reduction in pregnancy. (Prof. Anim. Sci. 28:560; Univ. of Nebraska)

RELATIONSHIPS BETWEEN RESIDUAL FEED INTAKE (RFI), SCROTAL CIRCUMFERENCE AND SEMEN QUALITY IN YEARLING BULLS
Data from Angus, Bonsmara, and Santa Gertrudis bulls were evaluated in five trials over 10 to 11 weeks conducted at different locations. Scrotal circumference and ultrasound fat thickness and ribeye area were measured at the start and end of trials. Semen samples were taken within 51 days of the end of trials when bulls averaged 12 to 15 months of age. There was no difference between high and low RFI bulls in ADG or scrotal circumference. More efficient bulls had lower feed consumption, higher gain:feed ratio, lower final fat thickness, and tended to have lower percent normal sperm. The authors concluded that “RFI is not associated with scrotal circumference or sperm motility but is weakly associated with sperm morphology”. (J. Animal Sci. 90:3937; Texas A&M Univ.)

DOES FORAGE AVAILABILITY AFFECT HETEROSIS FROM CROSSBRED COWS?
Hereford, Angus, and Hereford-Angus crossbred cows were compared under extensive range conditions. Cows were stocked to allow about 2 ½  lb or 4 lb forage per lb of cow weight. Production rate was determined as pounds calf weaned per female exposed to breeding. Crossbred cows at the higher forage availability produced at a rate 20% higher than crossbred cows at lower forage availability or purebred cows at higher forage availability (which did not differ) and 37% higher than purebred cows at lower forage availability. Heterosis will not compensate for poor nutrition. (J. Animal Sci. 90 E-Suppl. 2:331; Udelar School of Agronomy, Depart. of Anim. and Grass Production, Uruguay)

COMPUTER EVALUATION OF BEEF TO PREDICT PALATABILITY
The industry continues to search for objective methods of predicting eating quality of beef. A study was conducted to assess the value of computer vision systems (CVS) to classify beef as normal or dark, firm, and dry. Inside round muscles from 60 carcasses were evaluated 48 hours after slaughter. Scores from CVS analyses were highly correlated with presence of dark, firm, dry product. The authors suggested CVS could be used to reduce time and labor in determining color from a single visual image, thereby allowing more economical segregation of beef of lower consumer acceptability. (J. Anim. Sci. 90:4126; Univ. of Warsaw, Poland)

EFFECT OF CANADIAN-MEXICAN IMPORTS ON U.S. BEEF PRODUCTION
From 2006 through 2010, the U. S. averaged importing about 2 ¼ million cattle a year from Canada and Mexico. Of this total, about 55% were from Canada. However, because many of the Canadian cattle are finished and many Mexican cattle are stocker/feeders, Canadian cattle represent about 75% of the total cattle value at import. These imports account for about 8% of our total beef production. Factoring in that most of the Mexican-origin cattle are eventually finished in the US, about 65% of that total beef production derives from Mexico. (J. Agr. Sci., 2012, Vol 3. No. 2:201; USDA-ERS)