Effects of intrauterine infusion of gentamicin sulfate on bovine fertility

Gentamicin sulfate was administered by intrauterine infusion 10 minutes following first-service insemination at the rate of 200 mgs to dairy cows allotted at random to treatment and control groups to evaluate the effect on fertility. Pregnancy was determined by palpation of fetal membranes $\text{per rectum}$ 45–75 days after breeding.The first-service pregnancy rate was 43.8% in 233 treated cows and 51.7% in 232 control cows (P>0.1). The second-service pregnancy rate was 54.7% in 106 treated cows and 47.4% in 95 control cows (P>0.1). The pregnancy rate for both first and second services was 68.7% for 233 treated cows and 71.1% for 232 controls (P>0.1). Fertility was not enhanced by this treatment.