Beef Cattle Browsing – March 2013

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

BSE STATUS OF U.S. UPGRADED
The Scientific Commission of the World Organization for Animal Health (OIE) monitors incidence of bovine spongiform encephalopathy (BSE, so-called “mad-cow disease”). BSE status of the U.S. has been officially listed as “controlled”. The Commission has recommended this be upgraded to “negligible”, and formal approval is expected in May. This designation is the same as some of the largest beef exporters, including Argentina, Australia, and Brazil. The status of Canada and Mexico is not expected to change at this point. This upgraded designation should improve U.S. opportunities for exporting beef, or at least provide evidence based on science to counter exclusion of American beef. (http://www.oie.int/en/animal-health-in-the-world/official-disease-status/bse/list-of-bse-risk-status/)

CARCASS-BASED FACTORS AFFECTING FEEDING PERFORMANCE AND PROFIT
Increasing numbers of finished cattle are being sold on carcass value grids. In grid selling, value is based on carcass weight, not live weight. So, factors such as feed efficiency, ADG, etc. should be considered on a carcass basis. An analysis was conducted of 67,570 lots of steers and heifers fed during 2002-2008 in 212 feedyards in 6 feeding regions of the U. S.

Carcass-based feed efficiency was the most influential factor in determining both cost of carcass-based gain and net return per animal. The second most important factors determining value of carcass gain were carcass-based ADG and days on feed, by virtue of their overall effects on total carcass weight gain during feeding. Carcass-based ADG and days on feed were also the second and third most important determinants of net return per animal. Grid price variables (quality and yield, weight discounts, dark cutter) also affected value of carcass gain, but not to the extent of the effect of increased weight.

Highest profit was realized by feeding cattle until cost of carcass gain was higher than value of carcass gain. This point was reached by feeding to weights heavier than when comparing cost and value of gain on a live basis. (An important factor here is that, as animals finish, a progressively higher percentage of live weight gain is in the form of carcass weight.) In this study, profit was maximized at carcass weights of approximately 930 lb (1425 lb live) for steers and 845 lb (1290 lb live) for heifers. (Prof. Anim. Sci. 28:173; Colorado St. Univ., Elanco Animal Health, AgSpan)

NOTE: This study involves only the finishing phase of production. It should not be taken as an indicator that all cow-calf operations should produce steer calves capable of being profitably fed to 1425 lb. Cow-calf producers, even those retaining ownership through feeding and grid marketing, should consider all factors involved in their entire production and marketing system.

EFFECT OF GENETIC MARKERS FOR MARBLING ON HEIFER PERFORMANCE AND COMPOSITION
A group of 114 Angus heifers was divided into thirds based on degree of expression of two genetic markers previously found to be associated with marbling. Ultrasound for body composition was conducted at approximately one year of age.  Relationships were analyzed between genetic marker group with birth weight, weaning weight, yearling weight, rib fat thickness, rump fat thickness, intramuscular fat, and ribeye area. Heifers of the high marker group had greater rib fat thickness. There were no significant differences for other weight or composition traits. The authors concluded that genetic markers for marbling are not associated with weight or body composition, except for fat thickness which is the primary factor in Yield Grade. NOTE: More advanced techniques than markers are now available for genomic evaluation. (J. Animal Sci. 91 E-Suppl. 1:9; Mississippi St. Univ.)

CONSUMER PREFERENCE FOR GRASS-FED OR GRAIN-FED BEEF
A panel of 410 people varying in age range, gender, and farm or off-farm background evaluated samples from grass-fed and grain-fed cattle for tenderness, juiciness, and flavor acceptability. Low-Choice grade ribeye rolls were used in the study. Age, gender, and background did not affect results. Grain-fed steaks were found to be significantly more tender and juicy and higher in flavor acceptability. However, 24% of panelists preferred grass-fed beef overall. Based on these results, there appears to be a segment of consumers to which grass-fed beef can be successfully marketed. (J. Animal Sci 91 E-Suppl. 1:10)

PRODUCER PERCEPTIONS AND MISCONCEPTIONS OF IMPORTANCE OF COLOR IN COW HERDS
A total of 392 producers were surveyed while attending 16 meetings during 2010-2012 of the Genetics session of the Kentucky Master Cattleman program. The survey found that 66% of producers said color is “very important” in bull selection, while only 4% said it is “not important”. On the question of what does color of sire impact, 41% said “color” while 5% or less said “birth weight”, “weaning weight”, or “carcass traits”; however, 49% said color of sire affected “all of the above”.

As for how much Angus breeding is required for Certified Angus Beef, 11% said 100% Angus, 19% said 75% Angus, 36% said 50% Angus, 20% said 25% Angus, and 13% said 0% Angus. Only 13% gave the correct answer of 0% Angus. CAB requires a coat color of 50% or higher black to be preliminary accepted and then carcasses must be in the upper 2/3 of Choice or higher; but there is no requirement that CAB carcasses have any Angus genetic background. The authors concluded that some producers may make breeding decisions on misconceptions of requirements for value-added branded beef programs. (J. Animal Sci. 91 Suppl. E 1:32; Univ. of Kentucky)

NOTE: There is no doubt that Angus is the primary source of black color in the U.S. cattle herd; but numerous breeds have developed pure black or mostly black cattle, many of them genetically pure for color. Producers who market at weaning or after growing should certainly be aware of the presence and extent of any price differences based on physical features, including color.

SUMMARY OF EFFECTS OF MONENSIN (RUMENSIN®)
An analysis was conducted of 40 journal papers and 24 field reports published over the last 40 years of the effects of monensin on growing/finishing cattle. Monensin significantly reduced feed intake (3%), and significantly increased ADG (2.5%) and feed efficiency (6.4%); however, improvement in feed efficiency during the last 20 years has averaged 2.5-3.5%. Effects on feed intake and efficiency were higher when corn silage was part of the ration, which is more common in grower operations. Increase in ADG from monensin was diminished when ADG was above 2.6 lb/day. Because of these effects, monensin continues to be a feature of most cattle growing and finishing operations, especially for finishing. (J. Animal Sci. 90:4583;Univ. of Guelph, Elanco Animal Health)

JANUARY 1 CATTLE INVENTORY
Total number of cattle and calves and number of cows and heifers that have calved was down 2% compared to a year ago. Beef cows were down 3% and dairy cows were unchanged. Beef replacement heifers were up 2% but dairy replacements were down 2%. The estimated 2012 calf crop was down 3% compared to 2011. Cattle on small-grain pasture in Texas, Oklahoma, and Kansas were down 16%. Distribution of beef cows according to herd size was little changed, with approximately 45% of total cow numbers in herds of less than 100 head; 90% of beef cow operations had less than 100 head. (USDA)