Effect of flunixin meglumine on the corpus luteum and possible prevention of embryonic loss in Pelibuey ewes

The objective of the study was to determine the effect of flunixin meglumine (FM; a non-steroid antiflammatory drug) on the length of the estrous cycle and luteal phase, with the aim of increasing lambing rate and prolificacy in Pelibuey ewes. Two groups of females under a natural mating system were allotted to two groups: a FM-2 group, with ewes (n = 46) treated with 2.2 mg/kg of FM twice a day (06:00 and 18:00 h); a control group, with ewes (n = 50) given a placebo once a day (06:00 h). Both groups were treated for 8 days, starting at day 11 following mating. Blood samples from 10 ewes per group were collected every 3rd day, and from day 15 (mating = day 0) blood samples were taken daily, until ewes showed estrus or until day 21, whichever was first. The lambing rate was 58.0% and 56.5% for the control and FM-2 group respectively, while the length of the estrous cycle (19.4 ± 0.8 days) and luteal phase (15.3 ± 0.4 days) was longer (P < 0.05) in the FM-2 group, compared to the control group (17.6 ± 0.7 and 12.2 ± 0.3 days, respectively). The treatment with FM lengthened the luteal phase and estrous cycle in the ewes, however, it had no effect on lambing rate and prolificacy.