USE OF CHILLED AND FROZEN SEMEN IN FIXED-TIME ARTIFICIAL INSEMINATION PROGRAMS IN CATTLE

Abstract

Artificial insemination (AI) in cattle is a methodology that has been multiplied over the years in order to increase and improve animal reproduction. This technique consists of reducing the interval between generations and increasing the genetic values of animals. This study has as main objective to evaluate the rate of conception of cows, using cold and frozen semen. In this work, 4 nellore bulls were used for insemination in 200 nellore cows, in which they were separated into 4 lots of 50 cows, which were filed with the use of hormonal drugs to synchronize the estral cycle, starting in September and extending to October 2022. The bulls used underwent andrological evaluation in which bull I (cold semen) had the motility of 90% and vigor 3, bull II (cold semen) 80% motility and vigor 3, bull III (frozen semen) 70% of motility 3 of vigor and in bull IV (frozen semen) 65% motility and 3 of vigor. The diagnosis of pregnancy was made at 33 days gestation obtaining a conception rate of 65% of cold semen and 59% of frozen semen. The study showed that the cold semen method had a higher rate of conception, since it undergoes less manipulation process, unlike frozen semen.