IN VITRO CAPACITATION STATUS OF MERINO RAM SPERMATOZOA

Abstract

The objective of the present study was to determine the effects of individual
Merino rams on the in vitru capacitation status of ram spermatozoa. Four rams (eartag numbers R9, R12, R13, R16) of proven fertility were used in this study. Semen was collected by electroejaculation. The fresh semen was diluted at four dilutions (1:25, 1:20, 1:15, 1:10) in Hepes buffered synthetic oviduct fluid (HSOF). A sample of semen was collected at 0, 4, 8 and 12 hours and the capacitation status of spennatozoa determined. Capacitation status was analysed by univariate, analysis of variance to determine the effects of rams, incubation time and dilution rate on the capacitation status. During the 12 hours of incubation, progressively more spermatozoa became capacitated such that at the end of the incubation, 30.8 i 2.5% were uncapacitated, 40.9 i 0.9% were capacitated acrosome-intact and 29 1- 2.5% were capacitated acrosome-reacted. There were differences between rams in the capacitation profile. There was no significant effect of dilution on the capacitation rate. In conclusion, this study have established baseline of procedures for the detection of the capacitated spermatozoa using the chlonetracycline assay.