Efecto del protocolo de descongelación de semen sobre el porcentaje de preñez en bovinos lecheros

Abstract

In order to analyze the effect of the protocol of semen thawing on the percentage of final pregnancy, a trial was carried out in three farms in Santa Fe (Argentina). It was evaluated the time spent in taking out the straw from the nitrogen thermus till placing it in the thawing bath, as well as the temperature of the water together with the immersion time of each dose till its thawing, the length each dose remained in the inseminating gun and the performing of the insemination in each cow. The percentage of pregnancy was determined 60 days after the insemination through a transrectal ultrasound and the quality of the semen by means of the CASA system (Sperm Vision, Minitub, Germany). The protocol of thawing did not have an impact on pregnancy since every step was thoroughly controlled till the semen dose was inseminated. On the other side, the reproductive state varied significantly considering the operator performing the insemination and the time of the year. Even though more studies need to be carried out in order to go further into the topic, it can be anticipated that the higher impact on the percentage of pregnancy lays in factors other than the straw handling and the quality of semen.