Effect of Time of Feeding on Body Temperature of Wad Bucks and Pregnant Does in Tropical Environment

Abstract

This study aims to assess the impact of time of feeding on the body temperature of West African dwarf (WAD) goats. Twenty-seven goats (15 buck and 12 pregnant does) were used in this experiment. The bucks and gravid does were fed same experimental diet once daily at either, 06:00h, 12:00h or 18:00h in the morning, afternoon or evening, respectively. Rectal temperature (P<0.001) of bucks fed at 18:00h was higher than 12:00h fed bucks which was higher than 06:00h fed bucks. In contrast, pregnant does fed in the evening had lowest (P=0.009) axillary and rectal temperature while afternoon-fed does had the highest. Time of feeding induced increase (P<0.001) in axillary and rectal temperature of the bucks and pregnant does. The excursion ranges of temperature of morning, afternoon and evening-fed bucks was 0.42-0.79, 1.11-1.25, 1.15-1.19oC, respectively, while the excursion range of temperature of morning, afternoon and evening fed bucks was 0.17-0.19, 0.55-0.72, 0.45-0.47oC respectively. This study shows that time of feeding can entrain body temperature and animal physiological state can affect the temperature rhythm of animals. In conclusion, feeding bucks or pregnant does in the morning or evening may be an effective strategy to manage heat stress in the tropics. Feeding livestock in the afternoon should be avoided. Feeding in the evening may be adopted in the future due to the changing climate that will be accomplished by increased ambient temperature.