THE EFFECTS OF TEMPERATURE ON THE ENERGY-METABOLISM OF FED AND STARVED ANGORA RABBITS BEFORE AND AFTER SHEARING

Calorimetric measurements were made on 3 mature fed or 24 h starved male angora rabbits at temperature intervals between 18 and 30-degrees-C. Mean daily food intake was 105 g after compared to 88 g before shearing although similar at 30-degrees-C. Both metabolizable energy (ME) intake (KJ/kg W0.75) and heat production decreased with increasing temperature faster after than before shearing and by 36 and 23% respectively. Heat production of fed rabbits before shearing was similar between 18 and 22-degrees-C and post-shearing at 20 and 22-degrees-C but declined rapidly thereafter. Despite a similar food intake at 30-degrees-C, heat production was 14% greater after than before shearing. Equations relating heat product on and ME intake were similar pre- and post-shearing. When combined, net availability of ME was 0.53 and daily maintenance energy requirement was 443 KJ/kgW0.75. Mean water intake (g/day) was slightly higher after than before shearing. When expressed on a water: dry matter ratio, it was consistently higher before (3.8) compared to after (3.0) shearing. For starved rabbits, heat production was on average 9.5% higher after than before shearing. Post-shearing heat production declined with increasing temperature in a characteristic linear fashion. However after shearing it was similar between 18 and 22-degrees-C as observed during the feeding experiment. It is possible that shearing per se may have stimulated heat production particularly at these lower temperatures.