Evaluación cuali-cuantitativa de semen colectado con electroeyaculador (EE) de toros tratados con y sin tranquilizante

Abstract

The objective of this research was to improve the conditions of seminal collection with Electroeyaculador (EE), trying above all to preserve animal welfare during the collection process. It was performed with three adult bulls of Criollo phenotype, in two different situations: T1- without tranquillizer and T2- with tranquilizer (xylazine 2%) applied prior to collection. The semen was collected during 9 sessions, adding a total of 27 collections. To determine the effect of the tranquilizer during the seminal extraction, two stress indicators were evaluated; Cortisol and progesterone by means of blood samples taken at five moments: 20 and 5 minutes before, at the time of collection and 5 and 20 minutes after the collection, and also by means of fecal samples. In addition, qualitative and quantitative seminal characteristics were analyzed; Then processed, frozen and evaluated post-thawing in order to evaluate the effect of the tranquilizer. Fresh seminal analysis was not significant (P> 0.05) when comparing treatments, but in post-thawing if there were differences (P <0.05) for the HOST variable. Serum levels of cortisol showed significant differences at 5 minutes before and 5 minutes after collection, for P4 there were differences at 5 minutes after collection. These two hormones, when analyzed in feces at 8 hours after electroejaculation, were statistically different when comparing treatments. In conclusion, the use of xylazine does not improve the semen characteristics, however it decreases the stress generated after the process of electroejaculation in bulls.