• Journal of agriculture & life science
• /
• v.50 no.5
• /
• pp.163-172
• /
• 2016

Four growing Hanwoo cattle weighing 200±11.7kg were used within 4×4 Latin square design to establish nutrient requirements for Hanwoo growing steers under severe heat stress. The steers were fed four different energy level diets; 100%(control), 100%(E100), 115%(E115) and 130%(E130) of energy levels of growing Hanwoo steers based on total digestible nutrient level suggested by the Korea Feeding Standard for Hanwoo using timothy hay and commercial concentrate. The steers in the control were housed with no stress, whereas the steers in the other groups were under severe heat stress. The severe heat stress significantly decreased(p<0.05) true digestibility of dry matter(i.e. control 81.5% vs E100 79.1, E115 77.0 and E130 76.0, respectively). The severe heat stress and different energy intake levels did not affect blood physiological metabolites and body temperature of the growing steers. Based on changes in average daily gain by different energy intake level, the equation(Y=0.235X+115.03) of energy requirement of growing Hanwoo steers without changes in body weight was calculated, indicating that, compared with the present energy intake suggested by Korean feeding standard, 15.03% of dietary energy for maintenance of growing Hanwoo steers under severe heat stress should be increased.