Nascimento de bezerros normais após inseminação artificial utilizando espermatozóides criopreservados obtidos de epidídimos refrigerados de bovinos após a morte

Abstract

The objective of this study was to evaluate the morphological and functional characteristics of bovine spermatozoa retrieved from chilled epidydimides for long periods and cryopreserved. Bovine testicles were collected in abattoir, transported to the laboratory and stored at 5°C for 0, 24, 48h e 72 hours (n=10 for each storage time treatment group). The spermatozoa were retrieved from each epidydimides, evaluated and diluted in tris-egg yolk-glycerol 7% medium and cryopreserved in liquid nitrogen. The morphological and functional characteristics of the spermatozoa were analyzed in vitro, by microscopic evaluation and in vivo, using artificial insemination. Morphological alterations as sperm immaturity and motility reduction decreased after 72h of epididymides refrigeration and after thaw sperm were observed. The membrane and acrosome integrity were only affected in G48 and G72 groups after cryopreservation. However, the sperm capacity of fertilization postcryopreservation was sufficient to promote two pregnancies and birth of healthy calves from G24 h and G72h groups. These results indicated that recovery and cryopreservation of chilled epididymal sperm until 72h from dead animals is a viable option to preserve male gametes to compose a germplasm bank.