Effect of Different Levels of Egg Yolk on Cryopreservation of Black Bengal Buck Semen in Tris Egg yolk Citrate Fructose Glycerol Extender

Abstract

This study was conducted to assess the physical and morphological characteristics of fresh, pre-freeze and post-thaw black Bengal buck (<em>Capra hircus</em>) semen processed in Tris-egg yolk-citrate-fructose-glycerol (TEYCFG) extender containing 4 different concentrations (2.5, 5, 7.5 and 10%) of egg-yolk. Ejaculates were collected once a week for eight weeks from six mature bucks (48 ejaculates) using an artificial vagina. It was found that a general decrease in values of pre-freeze and post-thaw semen parameters such as progressive sperm motility (%), live sperm (%), acrosomal integrity (%) and positive sperm (%) in the hypo-osmotic swelling (HOS) test, but an over-all increase in abnormal spermatozoa compared to fresh semen for extenders containing different concentrations of egg-yolk. Best values for all the semen parameters were obtained using extender with 2.5% egg-yolk. Of all egg-yolk concentrations, the 10% egg-yolk supplement caused the highest percentage of abnormal sperm, which was significant (P<0.05), compared to 2.5% and 5% egg-yolk containing extenders, but non-significantly (P>0.05) different compared with 7.5% egg-yolk containing extender. Only progressive motility was significantly different (P<0.05) within extenders containing 2.5%, 5%, 7.5% and 10% egg-yolk. We conclude that Black Bengal buck semen can be cryopreserved effectively with tris-egg yolk-citrate-fructose-glycerol extender containing 2.5% egg yolk (V/V).