Beef Cattle Browsing
Editor: Dr. Stephen Hammack, Professor & Extension Beef Cattle Specialist Emeritus
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.
“CURLY CALF” SYNDROME
The American Angus Association reports the existence in Angus cattle of a genetic defect, initially called “curly calf”, but now officially known as Arthrogryposis Multiplex (AM). AM is characterized by calves born dead with curved spines, contracted or extended limbs, thin appearance, and a rough, curly coat. The Association received reports of such calves beginning in March, 2007. Reports on 48 calves were received between 9/06 and 9/15 of this year. All but one of those 48 reports involved the same ancestor on both sides of the pedigree, GAR Precision 1680. (According to the Association, the breeder of this bull, Gardiner Angus Ranch, is cooperating fully in efforts to examine this situation.)
Dr. Jonathan Beever, molecular geneticist in the Department of Animal Science at the University of Illinois, has been investigating this syndrome. In a report posted by the Association on 11/03/08 he stated “we have been able to identify the gene and mutation that we believe is responsible for this genetic abnormality.” The bull in question and some descendants have been widely used by Angus breeders in AI programs. Accordingly, five major AI organizations recently asked Dr. Beever to analyze DNA samples provided by them from 736 Angus sires, of which 61 (8.3%) were found to be heterozygous carriers of the gene.
The Association has developed policy and procedures for identifying and notifying the public of affected individuals, including appropriate designation on registration certificates. Dr. Beever assumes a recessive mode of inheritance for AM. Therefore, at this point, producers should generally not be concerned unless the 1680 bull is in the pedigree of both sires or potential sires and any females to be bred that also have 1680 inheritance. More complete information, including a listing of the 736 tested sires, can be accessed on the American Angus Association web page http://www.angus.org/ccs_info.html.
EFFECT OF SOURCE AND WEANING MANAGEMENT ON PERFORMANCE
Oklahoma State University researchers compared 249 ranch origin (RN) and 260 market-sourced (MK) calves. RN calves were obtained from the same operation in south central Missouri, where they had been vaccinated with a 7-way clostridial product at about two months of age. Those calves were either: 1) weaned and immediately shipped (WN) on 11/02 to the OSU research feedlot in Stillwater, OK; 2) weaned and kept on the ranch for 45 days (WN45) before shipping on 12/18 to the feedlot; or 3) weaned, vaccinated for the viral BRD complex, 7-way clostridial, and Mannheimia (followed 14 days later by BRD re-vaccination and vaccination for Leptospira) and held 45 days (WN45VAC) before shipping.
Two groups of MK calves of unknown management history were purchased by an order buyer at auctions throughout the Southeast, assembled in Mississippi, and transported 673 miles to the feedlot where one group arrived on 11/02 and the other on 12/19 or 12/21. About 24 hours after the November-shipped WN and MK groups arrived at the feedlot they were de-wormed and received the initial and 14-day-later vaccination protocol listed above. Also, about 24 hours after arrival, all December-shipped groups were de-wormed and WN45 and MK cattle received the same two-stage vaccinations as above. After processing, to expose RN calves to possible additional sources of disease some MK calves were commingled with calves from the three RN groups (COMM) while some of the RN groups and MK were fed separately resulting in the following experimental lots:
- WN commingled with MK
- WN45 commingled with MK
- WN45VAC commingled with MK
- MK (experimental control)
During the first 42 days on feed, RN gained slightly more than MK or COMM, but there were no significant differences in feed consumed or feed conversion. Sickness rate was significantly higher in MK (42%), intermediate in COMM (23%), and lowest in RN (11%). Mortality rates did not significantly differ, although MK was higher. Health treatment cost was significantly lower for RN.
For the first 42 days, WN consumed significantly less, relative to body weight, than WN45, WN45VAC, or MK but gain and efficiency did not significantly differ. WN45 (6%) and WN45VAC (10%) were significantly lower in sickness than WN (35%) or MK (42%). Health cost was significantly less in WN45 ($8.30) and WN45VAC ($8.93) than for WN ($13.24) or MK ($13.54). There was no significant difference in mortality among the three RN groups (ranging from none to 0.9%) but all tended to be non-significantly lower than MK (3.1%). There was no significant difference in USDA Quality Grade. However, MK had significantly lower, (i.e., leaner) USDA Yield Grade (2.10) than WN45 (2.33) and WN45VAC (2.44) which were both significantly lower than WN (2.77).
The authors concluded that weaning and holding on the ranch for 45 days resulted in improved health and performance compared to weaning and immediate shipment or purchasing and shipping high-risk auction calves. Also, calves held on the ranch had less ill effect from commingling with auction calves than did calves that were weaned, immediately shipped, and commingled. Numerous other reports have showed benefit from vaccinating at weaning and holding for 45 days on the ranch, but generally without comparison to contemporaries also held but not vaccinated. It may be that the primary benefit is weaning and holding for some time before shipping. (J. Animal Sci. 86:3146)
CALF AND FINISHED PRICE SPREADS
The difference between calf and finished prices continues to narrow. Three years ago in early November the difference between 450 lb steer calves and finished cattle was about $43/cwt. Two years ago that difference was $35, last year it was $23, and this year it was $18. Perhaps the recent decline in feeding costs will reverse this trend. Something else that has changed is the price difference between heavy calves and yearlings. Feeders generally favor yearlings over heavy calves. At this time three years ago 750 lb yearlings brought about $12/cwt more than 750 lb calves. This year that difference was about $6. It seems the value to feeders of older, ready-to-go yearlings has diminished in relation to the value of heavier on-feed weight. (USDA-AMS Weighted Average of Texas Auctions and National Slaughter Cattle Summary)
INDIRECT GENETIC SELECTION FOR EFFICIENCY
Measurement of feed efficiency requires measuring feed consumption, which involves considerable cost. There has been some indication from other reports that residual feed intake (RFI), a measure of efficiency, may be related to serum insulin-like growth factor-I (IGF-I). Texas A&M and Ohio State University researchers collaborated to study this subject in two lines of Angus that had been selected for 13 years for either high or low IGF-I.
In one study on a roughage-based ration, the two selection lines were similar in initial weight, ADG, feed consumption, feed conversion, and final weight. Though not statistically significant, there was a tendency for the low IGF-I line to have low RFI (higher efficiency). In a second study on a high-concentrate ration, selection line had no influence on weight, gain, consumption, or conversion. Again, there was a tendency for low IGF-I to have lower RFI, but only in bulls and not heifers. The authors concluded that genetic selection for postweaning IGF-I concentration had minimal effect on RFI. (J. Animal Sci. 86:2862)
Texas has officially had brucellosis-free status since February of this year. But that doesn’t mean we’re free from monitoring. Sexually intact cattle 18 months of age and older must still be tested before sale. That means all cattle sold. Cattle sold at markets are tested on-site. For private treaty, blood samples can be drawn by an accredited, private veterinary practitioner. Slaughter testing will probably continue indefinitely. We could lose our status if two infected herds are detected over two years, as Montana recently experienced. Dr. Bob Hillman, Executive Director of the Texas Animal Health Commission, recommends that producers have heifers vaccinated between 4 and 12 months of age by accredited veterinarians, particularly herd replacements and especially in the eastern portions of the state. (Texas Animal Health Commission News Release, 11/6/2008)
DIVERSITY IS GOOD
We often hear that some of our major crops have become less genetically diverse, and that this could lead to increased susceptibility to disease, etc. A team of university, government, and industry scientists has found that commercial poultry have also become less genetically diverse. In a world-wide sample of about 2500 birds, they found that genetic diversity has decreased by about half of that present in the 1950s, when large-scale commercial production became common. A drive down roads and highways in Texas makes it obvious that the genetic base of the beef herd is nowhere near as narrow as that of commercial poultry. But intense use through AI of popular sires, especially in some breeds, may warrant caution in some cases. (meatingplace.com, 11/4/08)
ANIMAL ID OUTSIDE THE U.S.
In last month’s edition of this publication, the Canadian national ID system was discussed. ID programs throughout the world may be of additional interest, especially in comparison to the current federal voluntary U. S. National Animal Identification System (NAIS). Colorado State University researchers studied systems outside the U. S. Represented were 12 countries or groups of countries (the European Union has a unified program and will be considered a “country” in the following summary) in Africa, Asia, Australia (and New Zealand), Europe, North America (Canada and Mexico) and South America.
Premises ID is mandatory in seven of those countries. Individual ID of cattle is mandatory in nine countries and voluntary in three. Group or lot ID, in place of individual ID, is allowed in 10 countries but not in two. Electronic ID is mandatory in four countries and voluntary in eight. Recording of movement of animals is mandatory in eight countries and voluntary in four. It is mandatory to retire individual animal ID numbers in eight countries and voluntary in four. Australia is the only country requiring mandatory compliance with all of these features, except for allowing group or lot ID. All of these features are voluntary in the current U. S. NAIS. It will be interesting to see which features, if any, evolve over time in NAIS. (Prof. Anim. Sci. 24:287)