A successful beef cattle nutrition program in an antibiotic-restricted world

This is because according to the FDA it will become illegal to use medically important antibiotics for growth promotion in animal production.

Furthermore, animal producers will need to obtain authorization from a licensed veterinarian in order to use medically important antibiotics for the prevention, control or treatment of a specifically identified disease.

Enacting the VFD law will quite possibly require animal agriculture to explore alternative practices to help prevent and control disease as the use of medically important antibiotics will become heavily regulated. The goal of this article is to review some of the alternative technologies and practices that might be incorporated to help prevent disease in beef cattle and improve growth performance.

Nutrition

Cattle that are stressed, such as newly arrived feedlot cattle, typically have depressed feed intakes, so therefore it is imperative that diets be formulated to account for this. Properly formulated diets for newly arrived, stressed feedlot cattle should contain higher concentrations of required nutrients to meet nutrient requirements in spite of lower feed intakes.

Increasing dietary energy by increasing the concentrate portion in receiving diets has been shown to improve cattle growth performance. However, it should be mentioned that increases in dietary energy may result in increased morbidity during the receiving period as well.

Feed intake management

Feed intake management consists of managing the amount of feed delivered to cattle in such a manner that cattle growth performance is improved. A feed intake management program, such as programmed feeding, utilizes net energy equations and delivers a prescribed amount of feed in order to achieve a targeted rate of gain.

The goal of programmed feeding is to maximize feed intake over the entire feeding period, which differs from the goal of maximizing feed intake on a daily basis as when cattle are “full-fed.” Programmed feeding also prevents the overfeeding of cattle by providing for more consistent feed deliveries compared to cattle offered feed on a full-fed basis.

Decreasing the variability of feed deliveries can be beneficial in improving cattle growth performance by decreasing the potential for digestive upset, as well as decreasing the amount of feed sorting and waste.

Environment

Providing bedding to feedlot cattle during periods of cold stress has been shown to improve cattle growth performance by insulating cattle from cold pen surfaces and decreasing mud by absorbing excess moisture within the pen.

Experiments have shown that providing approximately 2 pounds of bedding in the form of wheat straw per head daily improved average daily gain by 7 percent and feed efficiency by 6 percent.

Additionally, providing bedding to finishing cattle over the course of two winters in North Dakota improved average daily gain by up to 30 percent and feed efficiency by up to 31 percent.

It also improved final live weight, hot carcass weight, dressing percentage, ribeye area and the percentage of carcasses grading USDA Choice. Because cattle fed in a well-maintained environment have improved growth performance, it only stands to reason that health status would be improved as well.

Preconditioning

According to the latest USDA NAHMS survey, the perceived benefit of preconditioning calves before arrival at the feedlot on decreasing morbidity rose from approximately 50 percent in 1994 to between 70 and 90 percent in 2011.

Specifically, preconditioning practices surveyed consisted of acclimation to a feedbunk, a respiratory vaccine given at least two weeks before weaning, a respiratory vaccine given at weaning, weaning calves at least four weeks prior to shipping, castrating and dehorning calves prior to shipping and treating calves for internal and external parasites prior to shipping.

Preconditioning calves prior to arrival at the feedlot should help to decrease stress, which should help lower disease.

Low-stress handling

Anything that can be done to help decrease stress and increase animal comfort should help improve growth performance and health. Low-stress handling of cattle is becoming more widely practiced as the results are quite clear that when stress is decreased, health is improved.

Low-stress handling workshops and clinics are becoming more popular and even cattle handling equipment is increasingly being designed to provide for low-stress handling.

Direct-fed microbials and yeast products

Direct-fed microbials (DFM) and yeast products fall under the category “generally recognized as safe” according to the FDA, which prohibits any therapeutic or growth claims with such products. However, according to the latest USDA NAHMS survey, the percent of feedlot cattle fed a probiotic increased from 17.2 in 1999 to 53.8 in 2011.

The mode of action is not totally understood regarding the effects of feeding DFM or yeast products and subsequent effects on cattle growth performance and health, but proposed mechanisms consist of competitive attachment, antibacterial effects, modulating the immune response and positively affecting ruminal fermentation.

Genetic approaches

It has recently been reported that the susceptibility of cattle to bovine respiratory disease is moderately heritable.

Therefore, the discovery of the genotype and quantitative trait loci associated with the susceptibility of contracting bovine respiratory disease might be included in selection indexes, thereby allowing for the selection against genetic traits susceptible to bovine respiratory disease.

Conclusion

The VFD law is likely going to challenge the U.S. beef cattle industry to find alternative products and management practices to help decrease the incidence of disease in beef cattle while maintaining or improving growth performance.

Fortunately, the U.S. beef cattle industry has a long tradition of developing innovative technologies and management practices for beef cattle production, and hopefully the tradition will continue.

PHOTO: A feed intake management program utilizes net energy equations and delivers a prescribed amount of feed in order to achieve a targeted rate of gain. Photo by Mike Dixon.