Effect of flunixin meglumine on pregnancy rate of fixed-time inseminated dairy cows

Abstract

The aim of this study was to determine the effect of flunixin meglumine (FM) following timed artificial insemination (TAI) on pregnancy rate in lactating Holstein cows. Eighty-seven lactating Holstein dairy cows (30.3 ± 10.2 kg milk/day) with average 181 ± 152 days in milk (DIM) were given a 3 mg norgestomet ear-implant and a 2 mg injection of estradiol benzoate i.m. on Day 0. On Day 7, 0.53 mg i.m. of sodium cloprostenol was injected, and the implant removed on day 9. Two days later, 100 μg i.m. of gonadorelin was given followed by TAI 12 h later. Cows were randomly assigned into one of the following treatments: 1) FM Group (n=46) injected twice with FM given 12 h apart on the evening of Day 15 and the morning of Day 16, and; 2) Control Group (n = 41), that did not receive any further treatment. Pregnancy was detected by ultrasonography at Days 30 and 60 after TAI. Effect of treatment on pregnancy rate (PR) was analyzed by chi-square test. Cows treated with FM had higher pregnancy rate at 30 days (37% vs. 17%) and 60 days (37% vs. 15%) after TAI (P<0.05). In conclusion, injection of two doses of flunixin meglumine 15 days after TAI increased pregnancy rate of lactating dairy cows.