Testes funcionais de membrana e índice de prenhez utilizando sêmen crio preservado de tourinhos Tabapuã aos dois anos de idade criados a pasto e previamente selecionados pela CAP.

Abstract

ABSTRACTAccording to Brazilian College of Animal Reproduction (BCAR) criteria for post freezing semen classification, 12 young bulls were further selected to evaluate semen quality based on fast (TTRf) and slow (TTRs) termoresistence tests, hyposmotic test (HOST), induced acrossomic reaction by heparin (IAR), percentage of live sperm stained by trypan blue, and pregnant rate of first artificially inseminated females with semen from those bulls. Functional sperm test results were compared and their association with pregnancy rate and post-freezing motility were also evaluated. Bulls were further grouped according to post-freezing sperm motility (PFSM) and pregnancy rate (PR) to compare functional test results. Estimates of phenotypic correlation between pairs of spermatic parameters were also obtained. Differences (P<.05) between PFSM > 40% and PFSM < 40% were observed for TTRf, TTRs and HOST. No differences (P > .05) between functional test results were registered when grouped by PR > 50% and PR < 50%. Multiple regression model having functional, physical and morphological post-freezing semen test results as independent variables did not accounted (P>.05) for pregnancy rate variation even with a R2 = 0,83. No additional functional tests to BCAR standard criteria are necessaries to ensure high female pregnancy rate.Key words: semen, criopreservation, functional test, pregnancy rate, first artificial insemination first.