Effect of housing- and management-related stressors in late gestation and early lactation on the health, welfare, and performance of dairy cattle

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Various sources of stress, both housing and management related, for dairy cows in late gestation and early lactation may lead to poor health, performance, and welfare for both cows and their offspring. The overall objective of this project is to assess and evaluate the interactive and additive effects of late-gestation and early-lactation stressors on dairy cows. The specific objectives will be to: 1) identify the prevalence of housing, environmental, feeding and management related stressors on late-gestation and early-lactation cows in dairy farms; 2) associate these stressors with the health and performance of postpartum cows (i.e., disease incidence, milk production, reproductive performance) and neonatal calves (i.e., health, immunity), and 3) determine how these stressors interact and compound to affect these outcomes. A secondary objective is to validate maximum eye temperature as a novel measure of stress in transition cows by correlating that with other validated markers of stress. An observational study will occur in which the effect of potential stressors (including heat, stocking density, grouping, regrouping, dietary changes, disease) will be determined, particularly their additive effect, on the health and performance of cows and their offspring. To address the secondary objective, agreement between the fecal cortisol values and maximum eye temperature recording will be established. This information will be useful for identifying best management practices for housing and management of cows in late gestation and early lactation in dairy farms to improve cattle health, performance, and welfare, thus allowing Canadian producers to remain profitable and also increasing consumer confidence.