The effect of ambient temperature and activity on the daily variation in heat production of growing pigs kept in groups.

Abstract

In two experiments, pigs with initial weights of 20 kg were kept in climate-controlled respiration chambers. After a 7-day adaptation period at 22-24 degrees C the temperature was reduced in 4 degrees C steps to 8 degrees C and then increased to 24 degrees C. Each temperature treatment lasted 3 days. Feed contained 12 kJ metabolizable energy per g and was given at 93 and 83 g/kg^0.75 per day in experiments 1 and 2, respectively. Lower temperature increased 24 h heat production, but not 24 h activity. The mean activity periods moved from before and after feeding to after feeding, especially in the afternoon. During the afternoon, activity decreased at the lower ambient temperature, whereas metabolic rate remained constant. It is concluded that the effect of ambient temperature on metabolic rate depends on the time of day. (Abstract retrieved from CAB Abstracts by CABI’s permission)