Factors Affecting Biological and Economic Efficiency of the Beef-Cattle Enterprise

Non-Technical Summary:<br/>
The U.S. beef industry has gained production and economic efficiency through application of genetics, disease preventative measures, enhanced feed additives and growth-promoting agents, and managed nutrition interventions that capitalize on economic feed resources while enhancing feed efficiency. Continued emphasis on improving production efficiency is necessary to offset the inherently low production efficiency of both cow-calf and feedlot sectors of the industry. Increased reliance on corn co-products from ethanol production promises to improve production efficiency as the energy value of these co-products is similar to that of the grain they replace (corn or sorghum). However, health of the rumen and animal are sometimes compromised by their use; primarily from excesses of sulfur and phosphorus, plus the increased acidity derived from fast fermentation of these co-products in the rumen. Therefore, this project will contribute to increasing our understanding of feeding strategies and interventions to ameliorate negative factors associated with feeding DGS, and to step up intervention procedures to enhance production efficiency using alternative rumen modifiers. Incorporation of acute phase protein response will facilitate evaluation of remedies and alternative rumen modifiers while providing another tool to facilitate adoption of newly developed feeding and management strategies and interventions to include corn co-products and newly developed rumen modifiers by cattle producers.
<br/>Under the following two objectives: 1) to study effects of feed grade mineral oxides and multivalent avian-derived antibodies to reduce the effects of S on rumen fermentation and performance of cattle fed high concentrations of corn co-products from ethanol production; and 2) to determine effects of S inclusion, particle size, concentration of roughage, and inclusion of rumen modifiers such as ionophores and multivalent avian-derived antibodies on APP response and behavioral changes. I expect to determine the maximum nutritionally and physiologically permitted inclusion of corn co-products from ethanol production to facilitate economically efficient operation of feedlots as corn grain price rises. I also expect to develop strategies for use of rumen fermentation modifiers both conventional (roughage inclusion, ionophores and antibiotics) and alternative (multivalent avian-derived antibodies, essential oils, etc) to reduce health related effects of use of corn co-products from ethanol production.
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Approach:<br/>
Experiments to address objectives outlined above will be based on three types: acute response metabolism studies and long-term feedlot studies. Acute studies are proposed to determine mechanisms of action of interventions or stress factors on rumen metabolism and blood metabolite, including APP changes. Long-term feedlot studies are designed to test effects of interventions to feedlot performance prior to releasing results and recommendations to wider audiences. Lastly, super-imposing behavioral observations on acute and long-term studies will provide additional data regarding cattle adaptation to newly devised interventions and management strategies. An additional benefit of behavioral observations is acquisition of intervention-response data to share with feedlot operators so that they may better manage their feedlots.
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Progress:<br/>
2012/01 TO 2012/12<br/>
OUTPUTS: Findings were or will be reported during the Midwestern Section and the National Meetings of the American Society of Animal Science via abstracts and oral or poster presentations. In addition, several conference proceedings reported results of these investigations reaching multiplier audiences (feedlot consultants and feed industry representatives). Lastly, end-point users, cattle feeders, were informed of these findings via local meetings.
<br/>PARTICIPANTS: Jolene Kelzer. Graduate Student, University of Minnesota, St. Paul. Jeff Jaderborg. Graduate Student, University of Minnesota, St. Paul. Devan Paulus. Graduate Student, University of Minnesota, St. Paul. Jackie Popowski. Graduate Student, University of Minnesota, St. Paul. German Huber, Graduate Student, University of Minnesota, St. Paul. Ryan C. Fink. Postdoctoral Fellow, University of Minnesota, St. Paul. Grant Crawford. Extension Animal Scientist, University of Minnesota, St. Paul. Ryan B. Cox. Assistant Professor, University of Minnesota, St. Paul. Francisco Diez-Gonzales, Professor, University of Minnesota, St. Paul
<br/>TARGET AUDIENCES: Industry professionals, Academicians, Scientists, Undergraduate students, Graduate students, Consultants, Feed manufacturing nutritionists, Feedlot operators
<br/>PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
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IMPACT: We conclude that use of live yeast may only be warranted during cases of severe receiving stress in the feedlot. We confirmed that use of distillers grains diets at inclusion concentrations below 25% of diet DM dictates incorporation of urea to enhance microbial protein synthesis in the rumen. We have evidence of low frequency of distillers grains samples containing antibiotic residues with low concentrations of antibiotics. We also observed no serious evidence of microbial inhibitory concentrations in these samples.