Effect of tree shade on behavior and haircoat temperature of grazing dual-purpose cows in a hot and humid tropical environment

Abstract

We evaluated the behavior and skin temperature of dual-purpose cattle that grazed pastures having high (HC), low (LC), and no (NC) tree cover during the rainy and dry seasons in the hot and humid tropics of Mexico. We observed twenty-four adult cows (eight per treatment) over 24 days during each season, recording skin temperature and the time related to different daily activities. Across treatments, cows spent the same amount of time foraging during the rainy season (P > 0.05), but cows under HC spent less time during the dry season (P < 0.0001). During the rainy season, cows under HC showed more motivation to continue grazing than becoming restless or beginning rumination (P < 0.001) or roaming more than in other treatments (P < 0.001). During the dry season, cows under HC and LC also had less probability of initiating rest than NC (P < 0.001). Cows under HC had greater motivation to transition from grazing to roaming and less incentive to pass from rumination to rest than cows under LC and NC (P < 0.001). The frequency of water consumption was greater during the dry season (P < 0.001) and consistently high under NC (P < 0.0001). Skin temperature did not differ among treatments during the rainy season (P = 0.261), but during the dry season, it was greater under NC (P < 0.001). Tree cover improves cow behaviors by increasing the impetus to graze and perform daily activities, which contributes to reduced skin temperature during hotter seasons.