Abstract #252

# 252
Social stressors and their effects on immunity and health of periparturient dairy cows.
Ricardo C. Chebel*1,2, Paula R. B. Silva2, Karen Luchterhand2, Marcia Endres2, 1University of Florida, Gainesville, FL, 2University of Minnesota, St. Paul, FL.

Management practices during the periparturient period have been the focus of much research recently because during this period immune function, metabolism and health of cows are severely challenged. Responses to stress are often classified as behavioral, immunological, neuroendocrine, and autonomic. In production systems, understanding all facets of stress response is important to correctly predict the consequences of stressors to the health and performance of animals and to prevent costly managerial changes that have minimal impact on animal well-being and performance. Common stressors faced by periparturient animals are: regrouping, stocking density, and, for nulliparous animals, commingling with parous animals. In conventional dairies, feeding strategies during the periparturient period often require several group changes during the most challenging period of an animal’s life. Traditional weekly regrouping of prepartum cows increases competitive behavior at the feed bunk but it does not affect innate and adaptive immunity, metabolic parameters, health and production, as long as stocking density is not overwhelming and nulliparous and parous animals are housed separately. Stocking density of prepartum animals is often overlooked because these are non-productive animals. Although severe overstocking (200% of feeding space) of commingled nulliparous and parous pregnant animals produces important neuroendocrine and metabolic changes, when prepartum nulliparous and parous animals are housed separately, stocking densities of up to 100% of feed space do not seem to affect innate and adaptive immunity, metabolic parameters, and performance. In recent experiments, when animals were ranked based on feed bunk displacement, submissive animals were more likely to be diagnosed with metritis than dominant animals despite not presenting significant differences in metabolic parameters. With the advent of new technologies that monitor rumination, activity, and lying behavior, it may be possible to more easily identify submissive animals and create strategies to prevent diseases.

Speaker Bio
Dr. Chebel’s research is in production medicine with a focus on reproductive management of lactating cows and heifers along with other areas within similar fields.