Resumen de Efecto del hidroxitolueno butilado en la criopreservación espermática de ovinos y caprinos con o sin implantes de melatonina
Abigail Tabarez Rojas, W. García, M.J. Palomo
The aim of this study was to assess the effect of the inclusion of 5 mM of butylated hydroxytoluene (BHT) outside and inside of the breeding season and the application of melatonin implants on sperm quality in rams and goats. We used 6 Blanca de Rasquera bucks and 8 rams, 4 Aranesa and 4 Xisqueta breeds. The animals were divided into two groups with and without implants of melatonin inserted 60 days before semen collection by artificial vagina. Two ejaculates/day for 2 days/week were collected and mixed according to the experimental group, washed by centrifugation (twice for 10 min at 600g) and re-suspended in freezing medium with or without BHT (5 mM) supplemented with a final concentration of 15% powdered egg yolk and 5% glycerol in a Tris-based medium and refrigerated for 4 hours at 5 °C before freezing. Sperm viability after refrigeration and thawing was determined by eosine-nigrosine stain, no showing differences between treatments in any of the species. Curiously, only on goat sperm chilled in BHT medium, the viability was higher (P<0.01) in animals without that with melatonin implant. However, the time of year had an effect in both species possibly due to the age of the males.
