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.
MUST GENETICALLY ENGINEERED FOOD BE LABELED?
Some consumers advocate mandatory labels on food produced from genetically modified organisms (GMOs). Currently, 24 state legislatures have passed or have under official discussion some legislation of this sort. A recent report listed pros and cons of mandatory GE labeling:
1- Proponents say that in polls, when asked if the federal government should require such labeling a large majority of people said yes. But opponents note that in unprompted polls where the question was what additional labels people would like to see on food, less than 1% listed GE or GMO.
2- Proponents say consumers should have a choice of what food they eat and be able to pay more or less even if there are no differences in the product. Opponents note that consumers already have available products voluntarily labeled non-GE/GMO or organic.
3 – Proponents note that labels of calorie and nutritional content are mandated, so consumers also have the right to know if products are GE/GMO. Opponents counter that knowing what is in food is different from knowing the process used to produce it and that no labeling is required of any other production process.
On this issue, it remains to be seen whether emotion or facts will prevail.
(Am. Soc. of Anim. Sci. Taking Stock newsletter, 4/28/14)
AN ALTERNATIVE FINISHING SYSTEM ON PASTURE
Historically, some cattle were finished on ad lib concentrate feeding while grazing. A study was conducted to evaluate finishing on pasture with limited supplemental feeding. Heifers were either grazed for 129 days followed by high-concentrate feeding for 103 days (CON) or grazed for 138 days with unlimited self-feeding of a dried distillers grain-based supplement (SF). Average consumption of the supplement was 10.2 lb dry matter/day, which resulted in a one-third greater stocking rate for SF. Total forage utilization was not significantly different for the two groups. Heifers were slaughtered when fat cover over the ribeye was estimated to be 1/2 inch. Actual carcass fat varied so data were adjusted to 28% body fat, the amount generally associated with low-Choice marbling.
SF had higher ADG on pasture. CON had higher final weight (1247 lb vs. 1144 lb) and carcass weight (785 lb vs. 711 lb). CON had higher marbling score and larger ribeye area. SF were 94 days younger when slaughtered. There was no report of economic comparisons. The authors concluded that “the alternative production system may provide a viable option for marketing heifers in a cow/calf or yearling enterprise”.
(J. Animal Sci. E-Supple. 1:173; Univ. of Nebraska)
DO HEAT-SYNCHRONIZING DRUGS CAUSE TISSUE DAMAGE?
Injection-site damage from various antibiotics, vaccines, and anti-inflammatories has been well documented. Beef Quality Assurance education programs have been instrumental in reducing such damage. There has been some thinking that drugs used to synchronize heat for artificial insemination do not cause damage, or not as much. In this study, cows were injected once a week in different locations in the round with gonadotropin-releasing hormone (GnRH), prostaglandin, the anti-inflammatory flunixin (already known to cause extensive tissue damage), saline solution, or needle alone.
Prostaglandin and flunixin caused significantly more damage than needle only and marginally significant damage compared to GnRH. There was no significant difference in damage between prostaglandin and flunixin. Also, damage did not differ significantly between GnRH, saline, and needle only. The authors concluded that “the assumption that reproductive hormones cause little to no muscle tissue damage is probably incorrect, and more studies of the effect on meat quality should be performed”.
(J. Animal Sci. 89:1939; Texas A&M Univ., N. Dakota St. Univ.)
EFFECT OF ADJUSTED PELVIC AREA ON REPRODUCTION
A report of a recent study started with the statement “fetomaternal disproportion is the major cause of dystocia in heifers”. In other words, the major cause of calving difficulty is heifers relatively smaller than the calf. Pelvic area (PA) was advanced a number of years ago as a predictor of potential calving difficulty. But, in general, research has shown that dam weight, dam PA, and calf birth weight are all positively related.
This study included 438 Bovelder heifers, a South African composite developed starting in 1962 and including at various times Afrikaner, Angus, Bonsmara, Brahman, Brown Swiss, Charolais, Hereford, Holstein, Simmental, and South Devon. For some time in this herd, bulls used on heifers had maximum birth weight of 73 lb and maximum of those used on cows was 79 lb.
One month before start of breeding, heifers were weighed and within seven days of start of breeding PA was measured and Body Condition Score was visually scored; BCS was mostly 5 or 6. Heifers were AIed over 50 days followed by 42 days with cleanup bulls. Five rankings of heifers were made based on the following:
– 1) unadjusted PA,
– 2) PA adjusted to 365 days of age,
– 3) PA to heifer’s prebreeding weight ratio,
– 4) PA adjusted to median weight of all heifers,
– 5) PA adjusted to median BCS-adjusted weight of all heifers.
For all five rankings, 10% and 20% of lower PA heifers were hypothetically culled.
When all factors were included in a regression analysis, higher PA was positively related to prebreeding age and body weight and negatively related to BCS (which is not surprising since differences in BCS alone should not affect skeletal measures). In a similar analysis, higher calf birth weight was positively related to heifer birth weight, age at calving, and PA.
The only significant independent predictors of dystocia were calf birth weight, PA adjusted to median weight of all heifers, and PA adjusted to median BCS-adjusted weight of all heifers. With hypothetical culling by unadjusted PA alone, retained heifers were heavier, calving rate was higher, and calves tended to be heavier at birth, but dystocia rates were not different. The authors concluded that adjustment within age group of PA to either median weight or BCS-adjusted median weight improves accuracy in predicting dystocia.
(J. Animal Sci. 92:2296; Univ. of Pretoria, South Africa)
MARCHING TOWARD “SUSTAINABILITY”
Sustainability of beef production is a term being used a lot these days. Some of the largest foodservice businesses, and others, say they want their beef to come from sustainable production. But they’re having trouble defining “sustainable beef”. The recently formed Global Roundtable for Sustainable Beef is attempting to address this issue. The group is composed of:
– producer groups (including the National Cattlemen’s Beef Association, Canadian Cattlemen’s Association, and Cattle Council of Australia),
– commerce and processors (such as Cargill, JBS, Tyson, Elanco, Merck, and Dow),
– retailers (including McDonalds and WalMart),
– “civil society” groups (including organizations such as the National WildlifE Federation, Earth Innovation Institute, and Rainforest Alliance).
The Roundtable has preliminarily drafted the following sustainable beef principles:
- Natural Resource: Global sustainable beef stakeholders produce beef in a manner that identifies and manages natural resources responsibly and maintains or enhances the health of ecosystems.
- People and Community: Global sustainable beef stakeholders protect and respect human rights and recognize the critical roles that all participants within the beef value chain play in their community regarding culture, heritage, employment, land rights and health.
- Animal Health and Welfare: Global sustainable beef stakeholders respect and manage animals to ensure their health and welfare.
- Food: Global sustainable beef stakeholders ensure the safety and quality of beef products and utilize information-sharing systems that promote beef sustainability.
- Efficiency and Innovation: Global sustainable beef stakeholders encourage innovation, optimize production, reduce waste and add to economic viability.
Time will tell where this goes and what the impact will be on the various segments of beef production. (grsbeef.org)
SELECTING FOR EFFICIENCY VS. BODY COMPOSITION AND FEED CONSUMPTION
Genetic selection for efficiency continues to be researched and discussed. Long-term genetic selection research in cattle is costly and time consuming. Sometimes we can gain some insight from research on small laboratory animals. Mice were selected for either high heat loss/high maintenance (HM), low heat loss/low maintenance (LM), or maintained as unselected controls.
After 25 generations of selection, there was 56% divergence in heat loss and, compared to HM, LM consumed 34% less feed; but there was no significant difference in body weight or body composition. The authors concluded that selection for lower heat loss (higher efficiency) effectively reduced feed intake without effects on body composition. They attributed the reduction in feed consumption to reduced maintenance energy required. NOTE: Some short-term research suggests the same relationship exists in cattle.
(J. Animal Sci. 92:1886; Univ. of Nebraska)
DEHORNING – REMOVE, TIP, OR BAND?
A group of 40 crossbred steers and heifers, averaging 686 lb, were either:
– dehorned, by mechanical removal (M), using a keystone dehorner placed 1/2 inch below the base of the horn;
– tipped (T), cutting with a hand saw where the horn diameter was 1 1/4 inches;
– banded (B), using a high tension elastic rubber band at the base or;
– not dehorned for experimental control (C).
Vocalization was scored when treatment was conducted. Cattle were visually scored over the next 28 days for depression, gait/posture, appetite, lying, and horn bud healing.
Vocalization was higher for M and lower for T and C. Depression was higher for B. B exhibited more abnormal gait/posture and lying behavior. B also had higher appetite. During the first week, M exhibited less healing but during the second and third weeks B showed less. The authors concluded that M was a more painful procedure but recommended against B because of later adverse effects.
(J. Animal Sci. 92:2225; Kansas St. Univ.)
FOURTH TEXAS A&M GRASSFED BEEF CONFERENCE
The fourth Texas A&M Grassfed Beef Conference will be held on the campus of Texas A&M University May 29-30. Topics to be covered include overview of the US beef industry, defining natural/grassfed/organic, fundamentals of growing forage, cattle types suited for grassfed beef, forage-based nutrition for cattle, preventative herd health, handling cattle for wholesome beef, a demonstration of carcass fabrication, consumers and their expectations, a taste of Texas beef, marketing a unique product, and sustainability. To register go to https://agriliferegister.tamu.edu/BEEF or call (979) 845-2604.