The influence of purified porcine relaxin on the reproductive performance of sows following artificial insemination with fresh or frozen semen

Pregnancy rates and litter sizes following insemination of sows with fresh-extended and frozen-thawed semen averaged 71 vs. 53% and 10.6 vs. 4.4, respectively, and was not affected by the addition of 12.5 μg relaxin to semen. These results indicate no relaxin mediated effect on either pregnancy rate or litter size when sows are artificially inseminated with relaxin-supplemented semen. Key words: Artificial insemination, relaxin, sows