High temperature and humidity: impact on post-weaning

The purpose of this trial was to determine the effect of heat stress on animal performance (feed intake and growth).In two rooms were placed 360 piglets weaned at average age 26 days. In one, the ambient temperature varied from 26 °C at the start to 24 °C at the end. In the other, the temperature was maintained at more than 30 °C. In the first 14 days the greater heat had no impact on animal performance. Subsequently, feed intake was lowered in the pigs at 31 °C. This fall increased from 12 % between D14 and D21 to 26 % in the last week. Over the whole period the food intake was reduced by 13 %. At the same time, growth was impaired. At 40 days post weaning the overheated animals displayed a growth shortfall of nearly 4 kg, i.e., a lowering of average daily weight gain of 18 %. Thus during the hottest summer weather loss of performance post-weaning can be very marked. However, this effect is particularly pronounced when the temperature is high towards the end of the period.