Effect of different levels of egg-yolk on freezability of Jakhrana buck semen

The present study was designed to determine the effect of different levels of egg-yolk on freezability of Jakhrana buck semen. Six healthy Jakhrana bucks (BW=30 ± 2kg, age=12 ± 0.5 month) were used for semen collection. These bucks were maintained under semi-intensive system at Jakhrana Unit of C.I.R.G. Makhdoom, Mathura. A total of 48 ejaculates (6 bucks × 8 replicates) were collected twice a week using artificial vagina. Each ejaculate was divided into 4 groups (G₁, G₂, G₃ and G₃). The G₁ G₂, G₃ and G₄ were extended with Tris-egg yolk-citric acid- fructose-glycerol (TEYCFG) extenders containing 5, 10, 15 and 20% egg yolk level, respectively. Each ejaculate was evaluated for sperm motility, viability, abnormality, and hypo-osmotic swelling (HOS) response and acrosome integrity before and after freezing. At pre-freeze stage no significant (P>0.05) difference in sperm motility and viability was found among all groups. Sperm abnormality was significantly (P<0.05) higher in G₄ as compared to other groups (G₁ G₂ G₃). The HOS response and acrosomal integrity was significantly (P<0.05) higher in G₁ G₂ and G₃ as compared to G₄. However, no significant (P>0.05) difference was observedin HOSresponse andacrosomal integrityamong G₁, G₂ and G ₃. At post thaw stage,sperm motility,viability and HOS response was significantly (P<0.05) higher in G₁ and G₂ as compared to G₃ and G₄ Sperm abnormality was significantly (P<0.05) lower in G₂ as compared to other groups. The acrosomal integrity was significantly (P<0.01) higher in G₁ and G₂ as compared to G₃ and G₄ It is concluded that 10% egg yolk in Tris based extender may be the best for successful cryopreservation of Jakhrana buck semen.