Project Number: 6208-32000-007-00
Project Type: Appropriated

Start Date: Jan 02, 2013
End Date: Jan 01, 2018

Objective:
The long-term objective of this project is to identify alternative management practices that could be implemented to improve the health, well-being, and overall productivity of swine and beef cattle in production environments. To identify these alternative management practices, it is essential that we enhance our knowledge base regarding the potential use of non-antibiotic alternatives to antibiotic supplementation used to promote growth and enhance feed efficiency, and alternatives to mass medication treatment with antibiotics, and that we develop a better understanding of how an animal's flightiness or arousal level may influence its health, well-being, and overall productivity. Specifically, during the next five years, we will focus on the following objectives: Objective 1: Evaluate yeast and chromium as potential non-antibiotic alternatives to subtherapeutic/growth promoting concentrations of antibiotics in swine and cattle production systems. Sub-objective 1A: Evaluate feeding yeast products alone or in combination with chromium on the health and productivity of newly weaned calves. Sub-objective 1B: Evaluate differences in overall health and fecal shedding of bacteria following a Salmonella challenge in newly weaned pigs supplemented with yeast products. Objective 2: Elucidate immunological and metabolic differences among feedlot cattle with various levels of flightiness and arousal to determine whether different management strategies could enhance growth, health, and well-being of cattle. Sub-objective 2A: Determine the influence of cattle flightiness and arousal level on the adaptive immune response to a vaccine challenge. Sub-objective 2B: Elucidate potential differences in metabolic hormones in cattle of differing levels of flightiness and arousal.

Approach:
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.