RESUMO
BACKGROUND: Semen cryopreservation is essential in animal breeding programs for improving the availability of genetic resources from animals with high breeding value. OBJECTIVE: To evaluate the addition of Brazil nut extract as a replacement for egg yolk in bovine semen cryopreservation. MATERIALS AND METHODS: Semen was collected from five Nelore bulls and cryopreserved with the addition (treatments) of 0, 25, 50, 75, or 100% Brazil nut extract in the cryoprotectant medium. After thawing, spermatic cells were evaluated for morphology, plasma membrane integrity, spermatic kinetics, and in vitro fertilization. The experimental design was in randomized blocks, and the data were submitted to regression analysis. RESULTS: The minor-type and total defects, and plasma membrane integrity were affected (P < 0.05) as a function of egg yolk substitution with Brazil nut extract. There was a significant effect (P < 0.05) of Brazil nut extract addition on the spermatic kinetics and cleavage rate. CONCLUSION: The addition of Brazil nut extract in the cryoprotective medium as a substitute of egg yolk for freezing bovine semen negatively affects sperm quality and fertility.
