Effects of roof modifications on growth performance and physiological changes of crossbred beef heifers (Bos indicus)

Titaporn Khongdee
The objective of the experiment was to examine and evaluate growth performance and physiological changes of cattle raised under normal roof versus a modified roof. Ten Hindu Brazil x Brahman heifers were used in the experiment. The animals were divided randomly into two groups. They were used to evaluate the effects of modified roofing on the subjects' physiological responses to heat stress and performance under hot humid conditions. It was found that the modified roof (MR) offered a more
more » ... ent way to lower heat stress in the cattle than the normal roof (NR). The difference was sufficient to enable the NR at 14:00 p.m. to have a THI higher (P<0.001) than that of the MR. Roof temperature of the MR (35.67±4.28°C) was found to be lower (P<0.01) than that of the NR (44.49±7.61°C). Rectal temperature (RT) and average rate of gain (ADG) of the cattle kept under MR (39.02°C; 0.632 kg/d) was lower (P<0.01) and higher (P<0.01), respectively than the NR (40.05 °C; 0.350 kg/d) cattle.