Average body temperature was not affected by shade, except during a 21-day heat wave (8 hr/d of >86 degrees F) when the shaded cattle had a lower body temperature. Dry matter intake, average daily gain, and gain-to-feed ratio were higher for cattle that had shade. The shaded cattle also had heavier hot carcass weights. Shade had no effect on loin muscle area, fat depth, or marbling score.
Shade improved the performance of feedlot cattle, but did not completely eliminate the impact of a high heat load, as during the heat wave, the shaded cattle consumed 39 percent less feed (the unshaded cattle consumed 51 percent less feed).
Source: Journal of Animal Science. December 2010. Read abstract.