Effects of Moderate Heat Stress on the Growth Performance of Goat Kids

Abstract

To study the effect of moderate heat stress on the growth performance of goat kids, 10 cross-bred Saanen kids were assigned into 2 groups: The control group and the stressed group. Both groups were exposed using a controlled climatic chamber to 3 consecutive periods of 15 days each: Period 1, the control and the stressed group, were subjected to thermoneutral conditions. In period 2, the control group remained under thermoneutral conditions while the stressed group was subjected to moderate heat stress. In period 3, both groups were again exposed to thermoneutral conditions. Dry matter intake, body weight gain, water consumption, respiration rate and rectal temperature were recorded during the 3 periods. The results showed a depression effect of heat stress on the growth performance of kids, with no apparent ability to compensate there-after. Temperature-humidity index of 77 was show n to have a limiting effect on the growth rate of kids. This was clearly indicated by significant reduction in total dry matter intake, body weight gain and elevation in water consumption, rectal temperature and respiration rate.

These findings suggest that growth performance of goat kids during early stages of life can be adversely affected by exposure to moderate heat stress. The effect could be more pronounced if kids were exposed to heat stress during their early active stage of growth (4-6 months). To avoid such growth alteration it is advisable to have kids pass their active stage of grow th before the incidence of hot summer conditions.