Repeatability of the seminal and spermatozoa traits and fertility evaluation of stallions

Abstract

The aim of this study was to evaluate seminal and spermatozoa quality of stallions from North of Rio de Janeiro State in the breeding season and non-breeding season. Semen was collected from Mangalarga Marchador stallions, young (? 4 years) and adults (? 5 years). It was evaluated the pH, seminal volume, motility, vigor, concentration, the total number of spermatozoa, spermatozoa defects, and fertility. There was no variation between age category and breeding seasons in most of the traits. Although, there was a variation on spermatozoa defects between seasons, in that during breeding season we could observe more defects. Regarding the fertility, it was observed 60% of embryio recovery and 57.8% of pregnancy after embryo transfer. Concluding that one can collect and used the semen of these stallions for insemination in both breeding season without changing the quality, optimize the using of the genetic of the stallions.