REPRODUCTIVE PERFORMANCE AND MEAT PRODUCTION OF GILTS BRED AT PUBERTY AND RESTRICTED IN FEED INTAKE

Abstract

Sixty-one gilts, bred at puberty, were fed 1.2 kg of diet daily until day 84 of pregnancy, 1.4 kg to day 99 then 1.6 kg to farrowing. Thirty of their litters were weaned at 21 days (21 W), the others within 12 h of birth (0 W); 28 of the gilts were marketed 12 ± 3 days postweaning, the others were re-bred. Twenty-two unbred gilts were treated similarly to the bred gilts and 13 additional gilts selected at 91 kg body weight were used as conventional, market weight pigs. Age at puberty averaged 164 days; bred gilts were heavier than unbred at 85 and 100 days gestation. Number of piglets born averaged 9.1 total and 8.5 alive. Carcasses of the weaned gilts were lighter in weight than those of the unbred controls and had less backfat thickness than the lighter market weight pigs; total percentage yield of trimmed, deboned meat was not affected significantly. There were no significant differences in flavor, juiciness and tenderness of loin (m. longissimus) and ham (m. semimembranosus) meat between the market weight carcasses and those of the other four groups. Weaning to breeding interval for the 21 W and 0 W gilts bred for a second time averaged 23 and 38 days and embryo mortality was 15 and 21%, respectively, at 30 ± 3 days gestation. Key words: Puberty, gilts, feed restriction, once-bred, meat quality