Meat production from pigs which have farrowed 1. Reproductive performance and food conversion efficiency

Abstract

SUMMARY The reproductive performance and food conversion efficiency ofyoung female pigs (gilts) destined for slaughter after weaning their first litter were investigated using four treatment groups of 19 Landrace × (Landrace × Large White) gilts. In two treatment groups gilts were mated at pubertal heat and suckled for 5 to 11 and 35 to 42 days respectively. These gilts were slaughtered following weaning. A third group of gilts were conventionally mated at third oestrus and suckled for 35 to 42 days. These animals acted as controls for reproductive performace. The fourth treatment group consisted of unmated gilts, slaughtered at 118 kg live weight, which served as controls for food conversion efficiency, growth rate and carcass measurements. There were no significant differences in either the number or weight of piglets born in any of the treatment groups. The food conversion efficiency and growth rate of the mated gilts was significantly (P< 0·001) worse than that of the unmated gilts marketed at heavy weights. Of the mated gilts those mated at puberty and weaned at 35 to 42 days had the best overall feed conversion efficiency (4·56: 1) between the start of the experiment and weaning and required less food per piglet reared to 6 weeks of age than the gilts mated at third heat.