The effect of shade on sheep grazing pasture during summer conditions

Providing shade in situ in paddocks may lead to better animal welfare and/or improved sheep production outcomes. However, there are no replicated experiments detailing the effect of the provision of shade in situ under grazing during summer on behavioral, physiological, and production outcomes of sheep in the scientific literature. This study uses a replicated field experiment to examine the effect of provision of shade in situ to sheep under grazing on animal behavior, respiration rate, core body temperature (CBT), growth, and immunological function during summer in south east Australia. The experiment consisted of eight unshaded pasture plots and eight shaded pasture plots with an 18 m2 shade structure. Each plot was stocked with 20 sheep. Sheep with access to shade chose to use the shade in the hottest part of the day, reducing their 12 pm respiration rate to 64 breaths per minute (bpm) compared with sheep without shade at 98 bpm (P < 0.0001). However, the provision of shade had no effect on CBT, immunological function, or animal production. In the hottest part of the day, sheep without shade exhibited shade seeking behavior by either being located along the fence line (P < 0.0001) or at the water trough (P < 0.001). In conclusion, provision of shade in situ to sheep under grazing during summer conditions improved the affective state, and thus welfare, of the sheep by reducing the respiration rate needed to maintain thermostability.