Effect of Sources and Concentrations of Soybean Phosphatidylcholine on Diluted Goat Semen Equilibrated at 4

The objective of the present study was to determine the proper sources and concentrations of soybean lecithin (phosphatidylcholine, PC) to be used as substitute for hen egg yolk in extender for preserving goat semen. Two sources of soybean lecithin (20% and 95% soybean phosphatidylcholine; PC20 and PC95) and three concentrations (1%, 2% and 3% v/v) of PC20 and PC95 supplemented in Tris-citric acid-fructose (TCF) extender were tested. The TCF extender supplemented with 20% hen egg yolk was used as a control. Fresh semen samples were collected from 3 goats by artificial vagina. Seminal plasma was removed by centrifugation and sperm pellets were pooled together and divided into 7 groups according to types of extender. The diluted semen samples were kept at 4 ℃ (equilibration). The semen qualities including progressive motility, sperm viability, sperm plasma membrane integrity and tail abnormalities were evaluated before dilution and after 4 hrs equilibration. It was found that the progressive motility of equilibrated semen in egg yolk and PC20 extenders were higher than those in PC95 extender (P ＜ 0.05). Sperm viability was lower in 1% and 2% PC95 extender compared to other extenders (P ＜ 0.05). PC20 extender maintained the sperm membrane integrity and normal tail morphology at low temperature better than egg yolk and PC95 (P ＜ 0.05). It can be concluded that 20% soybean phosphatidylcholine supplemented in TCF extender at 1%-3% (v/v) is as effective as hen egg yolk to preserve goat semen during equilibration at 4 ℃ for 4 hrs.