EFFECT OF LEVEL OF FEEDING ON BREEDING PERFORMANCE AND CONCEPTUS DEVELOPMENT AT 60 DAYS OF PREGNANCY IN THE GILT

Abstract

A total of 132 Lacombe gilts were individually housed and fed 1.50, 2.25 or 3.00 kg of a 16% protein diet once daily from 35 days prior to mating to 60 days of pregnancy when they were slaughtered. The pregnancy rate (gilts pregnant/gilts on treatment × 100) of gilts on the 1.50-kg level of feeding was lower (P < 0.05) than that of the gilts on the 2.25- or 3.00-kg levels of feeding (66.7 vs. 85.4 and 90.7%). This was due to anestrus that occurred in 24% of the gilts on the 1.50-kg level of feeding treatment. Conception rate (gilts pregnant/gilts bred × 100) was not affected by the level of feeding. Increasing the level of feeding increased ovulation rate (12.6 ± 0.4 to 13.9 ± 0.3), ovarian weight (14.0 ± 0.5 to 17.7 ± 0.4 g), and uterine weight (1657 ± 79 to 1892 ± 64 g). There was no effect on the number, percent survival or weight of the fetuses; fetal attachment uterine tissue and fetal membrane weight; or allantoic and amniotic fluid volume. Fetal weight was correlated with fetal attachment uterine tissue and fetal membrane weight, and allantoic and amniotic fluid volume.