Effects of Dietary Lysine Supplementation on the Performance of Lactating Sows and Litter Piglets during Different Seasons

The effect of dietary lysine supplementation on the performance of crossbred lactating sows (n = 49, total 92 litters) and suckling piglets during the warm and cool seasons was studied. Sows were randomly allocated to one of two experimental diets, which were fed throughout a 28-day lactation period. Two diets were formulated based on corn-soybean meal with 6% wheat bran, containing 15% crude protein, and with or without 0.25% lysine-HCl supplementation. No interaction was observed between season and dietary lysine supplementation. Dietary lysine supplementation significantly (p<0.05) increased weaning weight (7.11 vs. 6.46 kg) and daily gain (0.20 vs. 0.18 kg) of piglets. During the warm season lactating sows had significantly lower feed intake (3.78 vs. 6.11 kg, p<0.01), higher weight loss (19.81 vs. 9.73 kg, p<0.01) and backfat loss (0.23 vs. 0.06 cm, p<0.01), longer interval from weaning to estrus (9.32 vs. 6.21 days, p<0.05), lower litter weight gain (42.13 vs. 52.90 kg, p<0.01) and lower daily gain (0.17 vs. 0.21 kg, p<0.01) than lactating sows during the cool season. The results indicate that the influences of dietary treatment and season were independent. The 15.0% CP lactation diet with 0.25% lysine-HCl supplementation did not improve the performance of lactating sows and litter piglets, which was impaired by the warm season. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 4 : 568-572)