Evaluation of mitochondrial activity in spermatozoids after collecting and posthawing in Boer and Alpine goats in autumn and spring

Abstract

Caprine spermatozoa undergo glycolisis and mitocondrial respiration to keep the necessary energy balance to their transportation and other cellular functions. An objective test to evaluate quantitatively and qualitatively mitochondrial activity in caprine spermatozoa was applied in the analysis of semen samples of 9 bucks from Boer (n=5) and Alpine (n=4) breeds. Samples were collected and frozen in TRIS medium in two different year seasons. Semen collection was performed using artificial vagina to obtain 135 ejaculates, which were used to post-collection and post-frozen extended in sildes. To determine mitochondrial activity, a citochemical procedure developed and validated for HRUDKA (1987) was used. The technique is based on the enzymatic 3,3-diaminobenzidine (DAB) oxidation, where the reagent is polymerized and attached to the mitochondrial membrane throughout the spermatic intermediary piece. A medium level of citochemical activity (IAC) was determined as being 74,37%, 74,37% during Autumn and 77% e 77,75% during Spring for Boer and Alpine breeds, respectively. For post-collection IAC levels were 85,62% and 85,93 and for post-frozen 66% and 67,25% for Boer and Alpine breeds, respectively. ANOVA test was used to evaluate breed, post-collection, post-frozen, IAC rates and year season parameters. Differences were not noticed for breed, IAC rates and year season. Nonetheless, there was a significant effect among samples for post-collection and post-frozen analysis (P<0,01). It was concluded that caprine spermatozoa collected in two different year seasons, in the two breeds, presented similar IAC levels, what makes evident that there is similar aerobic spermatic metabolism.