Andrological evaluation of bovine reproductors of Brazilian naturalized breeds

[paper presented at the Ibero-American Symposium "Conservation of Zootechnical Resources"]

Abstract

The objective of the present study was to evaluate andrological characteristics of bulls from Brazilian native breed and to verify the effect of cryopreservation on semen parameters. Animals from Pantaneira, Junqueira, Crioulo Lageano, Mocho Nacional and Curraleira breeds were utilized. Individual and in mass motility, and percentage of cell with intact chromatin, were similar for all animals. Except the animals from Pantaneira and Curraleira breeds, the remained showed seminal characteristics beyond the parameters recommended for cryopreservation. To evaluate the effect of freezing on semen characteristics, two males from Curraleira breed were used. All animals showed a decrease in overall and individual motility and an increase in the percentage of abnormal cells, after thawed. o changes in chromatin integrity were observed. The d crease in the percentage of cells alive and with intact acrosome after thawed was high r in the samples from bulls of th Curraleira breed than in the control bull. A variation was also observ d in the cleavage and blastocyst rates, being the lowest rates obtalned with semen fronl Curraleira animals. The results suggested that the structural and functional evaluation of the sperm cells after cryopreservation has to be done in all semen samples used to form a germplasm bank.