Publication Date

12-1-1997

Degree Program

Department of Agriculture

Degree Type

Master of Science

Abstract

Two-hundred-seventy-two sows were utilized in two trials to evaluate the effects of prostaglandin and pregnant mare serum on reducing weaning to estrus interval, increasing the degree of estrus synchrony and improving fertility at estrus resulting in improved pregnancy rates and subsequent litter performance. Sows were randomly allotted to treatments. In trial 1, sows were assigned to one of three treatments: T1 (n=18; l0mg of PGF2α /hd 24-48 hrs. after parturition), T2 (n=20; lOmg of PGF 2 α /hd at weaning) and controls (n=20). No differences (P>.05) were observed for survival rate and 21D litter wt. among treated and the control sows (83.71 vs. 81.57%; 103.89 vs. 108.36, respectively). As well, WEI, farrowing rate, and subsequent NBA did not differ between treat 1, treat 2, and controls (4.73 vs. 4.81 vs 4.75; 83.33 vs 80 vs 80%; 11.13 vs. 11.06 vs. 10.25, respectively). Trial 2 was performed with two experiments. The first experiment was performed in July 1996. Sows were assigned to one of two treatments: 1) controls ( n=52); 2) Administration of 60mg pregnant mare serum (n=39; injected at weaning). Farrowing rate was higher (P<0001) for PMSG treated sows than controls (100 vs. 63.46%, respectively). PMSG showed no significant (P>.05 effect upon improving number born alive among treated and control sows (11.13 vs. 10.57, respectively); however, there was a trend toward increased litter size among the treated sows. Experiment 2 occurred in February and March 1997. Sows were allotted to one of three treatments: 1) controls (n=42); 2) 60mg pregnant mare serum (n=42; administered at weaning); 60mg pregnant mare serum gamma radiated (n=39; administered at weaning). Data showed no significant difference among PMSG, GR-PMSG and controls for 5d estrus rate and 30d pregnancy rate (83.33 vs. 89.74 vs. 80.95%; 92.86 vs. 97.44 vs. 88.10%, respectively). Evidence from trial 1 showed that the use of prostaglandin did not enhance reproductive performance in swine. In addition, PMSG had little effect on improving fertility at post-treatment estrus and increasing number born alive. Although not statistically significant, trends toward larger litter sizes as well as improved 5d estrus rates and 30d pregnancy rates were evident in the treated sows. However, treatment with PMSG appeared to be effective in improving farrowing rates in the warmer months, perhaps masking the anestrus conditions typically detected during the summer.

Disciplines

Agriculture | Animal Sciences