Comparative Study Concerning The Artificial Insemination Techniques In Mares

摘要

The mare is a seasonal poliestric animal. The reproductive season lasts from April till September. Forobtaining valuable offspring, the artificial insemination (AI) with frozen semen needs to be encouraged, becauseonly a rigorous selection of the paternal line allows the accomplishment of this desideratum. This goal can alsobe obtained on the field with minimal costs. The main purpose of this work was to evaluate the efficiency of theartificial insemination with frozen semen in mares and to compare it to natural breeding.This study was conducted from 2012 to 2014 on 45 adult mares of different breed and age. The total numberof animals was divided in three groups: group I (n=8) was inseminated with frozen semen, group II (n=16)with refrigerated semen and group III (n=21) had natural cover. For each technique the following aspects wereevaluated: the number of ultrasound examinations per cycle, the number of AI or natural covers per pregnancyand the pregnancy rate for each mare. For the lots with AI, the dynamic of the follicular growth, the dimensions ofgranulosa prior to ovulation and the number of the semen straws per gestation were also assessed.The mares from Group I needed the most ultrasound examinations (n=11), compared to Group II (n=7) andGroup III (n=8). The pregnancy was obtained after a single AI with frozen semen, 4 with refrigerated semen and 8natural covers. The pregnancy rate was 62.5% for AI with frozen semen, 70.5% with refrigerated semen and 71.4%with natural breeding.Since similar results have been obtained by using these three reproductive biotechnologies, the use of artificialinsemination with frozen semen is the most recommended; mainly to benefit from the advantages that it offers.