Effects of Extender, Cryoprotectant and Freezing Protocols on Post-thaw Sperm Motility, Morphology and Viability of Three-yellow Cocks (Gallus domesticus) Spermatozoa

Abstract

Semen samples collected from 10 three-yellow cocks (Gallus domesticus) were pooled and treated to determine the effect of extender and cryoprotectant (experiment 1) and the effect of freezing protocol and cryoprotectant (experiment 2) on frozen/thawed semen quality. In the first experiment, semen samples were diluted 1:1 (v:v) with two different semen extenders, Beltsville poultry semen extender (BPSE) or modified Tyrode’s medium (TALP) and cryopreserved with either 6% dimethyl acetamide (DMA) or 8% dimethyl sulfoxide (DMSO). The best result (p<0.05) was obtained for TALP extender + 8% DMSO, with values of 57.32% for viability, 56.57% for normal morphology and 48.50% for motility. In experiment 2, two different freezing protocols (one-step and two-step) were evaluated. The results showed that there was no difference in post-thaw motility and viability of the spermatozoa (sperm) when either the one-step or the two-step protocol was applied with 8% DMSO. In contrast, the sperm motility and viability with the one-step protocol were better (p<0.05) than those with the two- step protocol when 6% DMA was used. This study indicated that from in vitro analysis, TALP with 8% DMSO was the preferred freezing solution for three-yellow cock sperm and this could be carried out using a one-step freezing protocol.