The use of injectable carbetocin improves seminal quality in Texel and Poll Dorset rams

Resumo

In sheep breeders, the use of rams with high genetic merit is based on frequent use of insemination, either with fresh or especially with frozen semen. Orihuela et al. (2024) found that carbetocin, a synthetic oxytocin, applied prior to semen extraction through electro-ejaculation, allowed greater quantity and quality of semen to be obtained. For these reasons, 

we worked on two experiments using carbetocin prior to obtaining semen from rams through an artificial vagina. First experience was using 8 Texel rams outside the reproductive season and the second experience was using 24 rams, 12 Texel males and 12 Poll Dorset during the reproductive season. In both cases they were separated into two groups, one group received the administration of 0.002 mg/kg of carbetocin (D, Decomoton®, Calier, Argentina) intravenously 20 minutes before semen extraction and the other group remained as a control (C). The following week the treatments were reversed. Outside the reproductive season, a significant increase in sperm concentration (P = 0.01) and total sperm (P = 0.02) per ejaculate was seen, with a positive trend an increase in volume (P = 0.08). During the reproductive season, an increase was observed in both the volume (P = 0.02) and the proportion of live sperm (P = 0.01), allowing a greater quantity of total live sperm to be obtained (P = 0.01). In conclusion the use of intravenous carbetocin 20 minutes before semen extraction allows improving semen quality by increasing the number of doses for artificial insemination and semen cryopreservation.