Start Date: Jan 02, 2008
End Date: Jan 01, 2013
Our research will focus on enhancing the performance, health, and overall well-being of beef cattle and swine in production environments. For the swine studies in Objective 1, several experiments will be conducted to evaluate various parameters associated with the health and productivity of swine following dietary inclusion of various nutritional supplements that have the potential to enhance innate immunity. Blood samples will be collected for analysis of hormones associated with the stress response, as well as hormones associated with the proinflammatory response following an endotoxin challenge. For cattle studies in Objective 1, calves will be weaned at approximately 6 months of age and fed various non-antibiotic products as potential modulators of immunity. Calves will be provided either a medicated diet or a non-medicated concentrate ration containing a non-antibiotic supplement for 21 days. Calves will be either inoculated with infectious bovine rhinotracheitis virus (IBRV) to determine if the non-antibiotic supplements provided any immunological protection to a viral challenge, or exposed to endotoxin to evaluate whether or not these non-antibiotic supplements enhance innate immunity. Feed intake and body weight will be routine measurements. Blood samples will be collected for analysis of hormones associated with the stress response, the growth axis, as well as cytokines and acute phase proteins associated with the immune response. For Objective 2, the research will focus on determining the relationships among animal temperament, stress responsiveness, and immune function in cattle as they relate to livestock management practices such as weaning and transportation. This information will be used to develop alternative management practices that enhance immunity, productivity, and overall well-being. Initial studies will determine the effect of animal temperament on the innate immune response following an endotoxin challenge. Subsequent studies will evaluate the effect of temperament on the response to management practices such as transportation. We will also evaluate the effects of weaning strategies on the innate immune system of beef calves. In these studies, weaning-age calves from a single breed will be categorized as to their temperament (temperamental or calm) based upon an objective exit velocity (EV) scoring system. Exit velocities will be obtained by determining the rate at which calves exit the working chute and traverse a fixed distance (1.83 m). In the first studies, we will assess the innate immune response to an endotoxin challenge based upon temperament. Blood samples will be collected and serum analyzed for hormones associated with the stress response, as well as cytokines associated with the acute phase immune response following the endotoxin challenge. In the subsequent studies, we will assess the stress responsiveness following management practices such as transportation and weaning. Body weights, blood samples, and rectal temperatures will be routine parameters measured for these studies. Blood samples will be analyzed for stress hormones, as well as cytokines associated with the immune response.