Post-mating diclofenac vs. carprofen treatment on serum progesterone levels and reproductive outcomes in Hungarian-Merino ewes during the non-breeding season

The maternal recognition process is crucial for the establishment of healthy pregnancy. In this process, anti-luteolytic applications are one of the main reproductive strategies to manage the embryonic losses and maximize reproductive profitability in farm animals. The aim of this study was to investigate the efficacy of post-mating NSAID treatments on reproductive parameters (pregnancy rate, lambing rate, multiple birth rate, litter size) and serum progesterone levels in ewes stimulated with progesterone non-breeding season. For this purpose, two different experiments (diclofenac and carprofen) were conducted in the same ewe flock induced with short-term progestogen-based protocol in the non-breeding season for two consecutive years. In experiment 1 (n = 85), 42 ewes were injected with 2.5 mg/kg diclofenac on the 9th and 10th days post-mating, and the rest were not treated and served as control. In experiment 2 (n = 82), 40 ewes were injected with 1.4 mg/kg carprofen on the 9th days post-mating, and the rest were not treated as control. In both experiments, blood samples were collected from all ewes on days 9, 12 and 13 post-mating to measure serum progesterone levels. In both experiments, there were no differences both reproductive parameters and serum progesterone levels when compared to the control groups. It was concluded that post-mating diclofenac and carprofen treatments in the critical period have no significant effects on both reproductive parameters and serum progesterone levels in ewes in the non-breeding season.