Effect of Virgin Coconut Oil Combined with Coconut Milk on the Quality of Chilled and Frozen-Thawed Bull Semen

Abstract

The aim of this study was to assess the effects of virgin coconut oil (VCO) combined with coconut milk (CM) on chilled and frozen–thawed quality parameters of bull sperm. Twenty four semen samples were collected from four bulls. Samples were diluted in Tris extender containing 0% (control only 3% CM) in Tris-base extender), 2%, 4%, 6%, 8% VCO mixed with 3% CM and 20% egg yolk (group B). Extended samples were divided into two fractions, one was chilled at 4°C for 24, 72 and 144 hours and the second fraction packed into 0.25 ml straws and frozen in liquid nitrogen for 7 and 14 days. Subsequently, chilled samples and the straws were thawed and evaluated for sperm motility by Computer Assisted Semen Analyzer (CASA), viability, acrosome integrity, morphology (eosin-nigrosin) and membrane integrity (hypo-osmotic swelling test). Higher (p < 0.05) percentage of sperm parameters was observed in the positive control group in chilled semen, followed by 8% VCO  compared to the other concentrations of the VCO. There was no significant difference in morphology between positive control and all other treatment groups in chilled or frozen-thawed semen. The positive control group was higher in all sperm parameters measured when compared with treated groups in frozen-thawed semen. In conclusion the results showed that the mixture of VCO with coconut milk applied in this study could not maintain the function of bull sperm after chilled and frozen-thawed better than the positive control.