Some Characteristics Associated with Feed and Breed Differences in Ovulation Rate in the Gilt

Abstract

Forty-eight gilts of the Chester White, Hampshire and Poland China breeds were individually fed a basal ration, a basal ration plus glucose or a basal ration plus corn oil for approximately 14 days prior to their third postpuberal estrus. The basal ration was fed at the rate of 2.2% body weight per day, the glucose at 1.72% and the corn oil at 0.69% (isocaloric to the glucose). Feeding either corn oil or glucose increased ovulation rates, weight gains and backfat gains significantly over basal-fed controls. Blood glucose levels were elevated (P<.06) by approximately 10 mg./lOO ml. in glucose-fed gilts and 20 mg./lOO ml. in corn oil-fed gilts. Significant breed differences were found only in ovulation rates and weight gains. The Chester Whites had the highest ovulation rates and the lowest weight gains, while the Poland Chinas had the lowest ovulation rates and the greatest weight gains. The between-breed regressions of ovulation rate on the other three characters studied were negative, whereas the between-feed regressions were positive. The within-group regressions were nonsignificant. Copyright © 1967. American Society of Animal Science . Copyright 1967 by American Society of Animal Science