You hear this term a lot, but did you know, that especially during heat stress bigger pigs suffer more than smaller or younger/lighter pigs?
Bigger pigs are more prone to heat stress and the reduction in growth performance is greater than for smaller pigs.
Figure 1 shows the performance loss in 25, 50 and 75 kilogram (kg) pigs when the temperature was increased from 14°C to 35°C. Average daily gain (ADG) starts decreasing when 75kg pigs were exposed to temperatures above 23°C, while for 25kg pigs ADG starts to decrease when exposed to temperatures above 27°C.
Figure 2 shows critical temperatures at various body weights.
Figure 1 Effect of ambient temperature on the average daily gain of grower-finisher pigs (©2019 Renaudeau et al).
Figure 2 Pig body weight has a significant effect on the critical temperature for average daily feed intake (ADFI) and average daily gain (ADG) (©2019 Renaudeau et al).
It is clear that older/heavier pigs are less resistant to heat and are therefore, more concerned with their comfort and well-being in the summer. Younger/lighter pigs up to about 8 weeks of age or 23 kg can tolerate heat but are extremely sensitive to cold.
Farmers will do whatever they can to keep all sizes happy, but this is a tough job. Luckely there is a variety of products that can support where-ever this is needed!