2011 Annual Report
1a.Objectives (from AD-416)
Our primary objective associated with this subordinate project is to determine if live yeast or yeast cell wall supplementation improves the overall health and performance of cattle during the early phases of the feedlot period.
1b.Approach (from AD-416)
Twenty-four recently weaned calves weighing approximately 500 pounds will be transported to our research facility. Upon arrival, all calves will be weighed and placed into one of three treatment groups in a manner that balances the body weights across treatments. The three treatment groups will consist of:.
1)Control group, n = 8 calves, fed a standard receiving diet;.
2)Live Yeast group, n = 8 calves, fed the Control diet containing live yeast; and.
3)Yeast Cell Wall group, n = 8 calves, fed Control diet containing a yeast cell wall product. Calves will be fed their respective diets for 21 days. On day 22, all calves will be fitted with indwelling jugular catheters and probes to measure rectal temperature. On day 23, all calves will be subjected to an immune challenge to determine their innate immune response. Serum samples collected during the study will be analyzed within the Livestock Issues Research Unit for hormones and proinflammatory cytokines associated with the stress and immune response. Additionally, performance data will be collected to determine if the yeast supplements alter performance prior to and after the immune challenge.
The overall focus and objective for this project are to evaluate the potential health benefit of supplementing cattle with various yeast products upon arrival into a feedlot. During the past year, significant progress was made regarding the potential benefit of providing incoming beef cattle with a yeast supplement upon arrival into a feedlot. Specifically, an initial study conducted indicated that supplementing a group of high-risk receiving cattle with both live yeast and a yeast cell wall product reduced basal rectal temperature, an indication that the cattle were healthier. Supplementation of the yeast and yeast cell wall product also reduced the stress hormone response to an acute immune challenge, thus indicating that the supplements provided a level of immunological protection. Additionally, during the entire feeding period, supplementation with the yeast products reduced overall morbidity and improved growth performance. Results from this initial study were presented at a national scientific meeting, as well as at several regional meetings, and were of great interest to beef cattle scientists, industry groups, and beef producers. Additional studies were planned to confirm the initial results.