Effects of heat stress abatement on behavioral response in lactating dairy cows prior to and following an intramammary lipopolysaccharide infusion

作者：T.N. Marins, Ruth M. Orellana Rivas, Y-C. Chen, Victor H.L.R. Melo, Zhou Wang, Hong Liu, Jing Gao, C.G. Savegnago, A.M. Roper, J.K. Bernard, Pedro Meléndez, Sha Tao · 发表于：Journal of Dairy Science · 年份：2024 · DOI：10.3168/jds.2024-25298 · 被引用次数：7 · 研究领域：Effects of Environmental Stressors on Livestock、Animal Behavior and Welfare Studies、Reproductive Physiology in Livestock

The assessment of animal behavior serves as a valuable approach to identify illness and animal responses to environmental stimuli. Both heat stress and mastitis are reported to affect the behavioral responses of dairy cattle. However, little is known about the effects of heat stress on the lactating cow's behavioral responses to mastitis. The aims of the current study were to evaluate the effects of deprivation of evaporative cooling on behavioral responses of lactating dairy cows before and following mammary inflammation induced by intramammary LPS (IM-LPS) infusion and to characterize the effect of deprivation of evaporative cooling on feed sorting in lactating dairy cows during summer. Multiparous mid-lactating Holstein dairy cows (n = 18, parity = 2.4 ± 0.6, DIM = 136 ± 61 d) were randomly assigned to: evaporatively cooled (CL, n = 9) or not cooled (NC, n = 9) for 36 d (average temperature-humidity index = 78.4). The evaporative cooling system included misters and fans. Misters were installed on the front face of each fan, which was placed over both feed bunk and freestalls. On d 30, the left rear quarters of a subset of cows (n = 14, 7 per treatment) were infused with a bolus of LPS (10 µg of Escherichia coli O111:B4 LPS). Feeding and resting behaviors were recorded throughout the experiment using automated sensor devices (NEDAP). Sorting activity based on particle size separation using a Penn State Particle Separator was assessed at d 3, 16, and 26 of the experiment. Be...