Location: Livestock Issues Research
Project Number: 6208-32000-007-00
Start Date: Jan 02, 2013
End Date: Jan 01, 2018
Our research will focus on enhancing health, performance, and overall well-being in beef cattle and swine during periods of production known to be stressful, such as weaning and transition into a feedlot. For Sub-objective 1A, an experiment will be conducted to evaluate the inclusion of yeast products and chromium in the diets of weaned beef calves as a means to prime and enhance their immune system. Blood samples will be collected for whole blood cell analysis and analysis of hormones associated with the immune and stress responses. Blood samples will also be collected to evaluate the immune cell responses to in vitro immunostimulation. Feed intake and body weights will be recorded to evaluate the potential influence of the various feed supplements on growth performance of the calves. For Sub-objective 1B, an experiment will be conducted to determine if supplementing the young pig's diet with a yeast cell wall (Saccharomyces cerevisiae) product will enhance growth performance, reduce Salmonella-induced sickness, and reduce tissue Salmonella contamination in pigs that have been orally inoculated with live Salmonella. Blood samples will be collected and analyzed for cortisol and pro-inflammatory cytokines. Tissue and fecal samples will be collected to evaluate the influence of diet on the presence or absence of Salmonella. Feed intake and body weights will be collected to evaluate the potential influence of the yeast cell wall product on pre- and post-challenge growth and performance. For Sub-objective 2A, crossbred Angus calves will be used in an experiment to determine if the level of flightiness and excitability displayed by an individual calf will influence the adaptive immune response to vaccination. Calves will be categorized as to their level of flightiness and excitability based upon an objective exit velocity and subjective pen scoring system determined at 28 days prior to and at weaning. On day 28 post-weaning, calves will be vaccinated with a novel vaccine to evaluate their primary immune response. Blood samples will be collected and analyzed for cortisol, total IgG, and vaccine-specific IgG concentrations. For Objective 2B, an experiment will be conducted to determine if the level of flightiness and excitability displayed by an individual calf will influence its metabolic response to various metabolic challenges. Calves will be categorized as to their level of flightiness and excitability based upon an objective exit velocity and subjective pen scoring system determined at 28 days prior to, and at weaning. Blood samples from calves will be collected during routine feeding, and during a period of feed restriction in which the calves will be fed at a level of 10% below their net energy for maintenance requirement. Blood samples will be analyzed for cortisol, glucose, non-esterified fatty acids (NEFA), blood urea nitrogen (BUN), insulin, hydroxybutyrate, and creatinine concentrations to evaluate the metabolic response of the calves during each feeding regimen.