The use of nonsteroid anti-inflammatory drugs (NSAID) after artificial insemination in high milk yielding cows.

Reproductive performance is markedly reduced during high milk production. In this study, we used a combination of meloxicam, a non-steroid anti-inflammatory drug (NSAID), known to inhibit the synthesis of prostaglandins, with or without GnRH, a hormone commonly used to induce ovulation or luteinization in cattle. The effects of meloxicam (0.5 mg/kg BW) alone or in combination with GnRH (100 µg of gonadoreline) were evaluated in cows with medium (MMY, n = 59, 30-40 L milk at the 10-day interval before and after AI) and high (HMY, n = 57, > 40 L) milk production from 90 to 120 days in milk. Cows (n = 46) received ovsynch with double PGF2α at day 7 and 8 after the 1st GnRH; 24 of these cows received GnRH at day 7 after AI and NSAID at day 15 after AI (meta-ovsynch, OS+GnRH+NSAID), the rest (n = 22) was the control group (OS). Furthermore, cows (n = 70) at natural estrous were divided randomly into 3 AI groups: (1) AI (n = 24), cows received only AI, (2) AI+NSAID (n = 24) cows received NSAID 15 d after AI and (3) AI+GnRH+NSAID (n = 22) cows received GnRH 7 d after AI and NSAID 15 d after AI. Pregnancy diagnosis was performed by PAG 28 d after AI. Z0.5 criterion was used to compare the conception rates (CR). Between ovsynch groups no significant difference was observed. Among AI groups, the CR was higher (P = 0.012) in the AI+GnRH+NSAID (72.73%) than in the AI group (41.67%). Furthermore, in HMY cows, significantly higher CR was recorded in the AI+GnRH+NSAID (70%) compared to the AI+NSAID (25%) or the AI (42.86%) groups; in MMY cows, CR was higher (P < 0.05) in the AI+NSAID (83.33%) and AI+GnRH+NSAID (75%) compared to the AI group (40%) It seems that different protocols could be used depending on the milk yield at AI.