Fertility of Katahdin ewes laparoscopically inseminated with refrigerated or cryopreserved semen in the tropics

Abstract

The objective of the study was to compare the semen fertility and pregnancy rate in a katahdin sheep herd by laparoscopic insemination with refrigerated and frozen semen in a tropical environment. The breeder and twenty bellies of the katahdin breed were used. Two evaluations were performed to assess the quality of the semen according to its macroscopic and microscopic characteristics and the females were synchronized with intravaginal devices with 0.3 g of natural progesterone (CIDR®, Zoetis), plus a dose of 400 IU of human chorionic gonadotropin (HCG). Fertility was higher (p< 0.05) (30% pregnancy) in ewes inseminated with frozen semen, compared to 20% pregnancy in those inseminated with cold semen. The evaluated seminal fertility variables demonstrated that the semen in katahdin stallions in a tropical environment is of good quality for handling in the practice of artificial insemination. It is concluded that the breed group of the animals used responded satisfactorily to the synchronization and the semen was within the parameters established for the species, it also tolerated the manipulation, in terms of insemination by laparoscopy, it is a crossbreeding technique that is not widely disseminated in the region however, the study developed suggests further research to provide sufficient knowledge to strengthen the procedure and thereby increase conception in ewes bred.