Lack of effect of regular movement and of mixing groups on the performance of growing pigs

Abstract

The effect on pig performance of 2 methods to reduce pen stocking densities was examined using 228 pigs growing from 20 to 100 kg in 7 commercial piggeries. Pigs either: (i) remained in the same pen for the full period; (ii) were moved to a different pen every 4 weeks; or (iii) were mixed, after 8 weeks when they weighed about 50 kg, with half the pigs from a second pen and then moved to 2 new pens. Pigs were fed ad libitum the diet normally used on each farm. Daily gain, feed:gain ratio and backfat depth were unaffected by treatment (P> 0.05). There was an indication (P<0.10) that movement increased daily feed intake and this may have been associated with a slight decline in carcass gradings. Fighting occurred when the pigs were mixed after 8 weeks, but no adverse effects were apparent at slaughter. Floor space allowances for growing pigs can be increased by 2 movement strategies (moving or moving-and-mixing) commonly used by producers, with only slight, if any, detriment to performance.