Cryoprotective Effect of Glycerol Concentrations on Indian Red Jungle Fowl (Gallus Gallus Murghi) Spermatozoa

Abstract

Semen cryopreservation protocols for wild avian species need to be optimised in order to achieve optimum post-thaw sperm quality and fertility. The present study was designed to evaluate the cryoprotective effect of different glycerol concentrations (11%, 15% and 20%) on post-thaw quality, recovery rates, absolute livability index and fertility of Indian Red Jungle Fowl (Gallus gallus murghi) semen. Semen was collected from eight mature cocks and cryopreserved for storage at −196 °C. Frozen semen was thawed at 37 °C for 30 s and assessed for motility, plasma membrane integrity, viability and acrosome integrity at 0, 2 and 4 h incubation at 37 °C. Percentages of motility, plasma membrane integrity, viability and acrosome integrity were recorded higher (P<0.05) post-thaw at 0, 2 and 4 h at 37 °C with 20% glycerol compared to 15% and 11% glycerol. Likewise, recovery rates (%) of aforementioned parameters after cryopreservation and absolute livability index were observed highest (P<0.05) with 20% glycerol. By comparing values of R² after multivariate regression analysis, least negative effects of hours of incubation were observed on semen quality in extenders with 20% glycerol followed by 15% and 11% glycerol. The fertility outcomes (number of fertile eggs, fertility [%], number of hatched chicks, percent hatch and hatchability of fertilised eggs) were recorded higher (P<0.05) with 20% glycerol followed by 15% and 11% glycerol. It is concluded that the concentration of 20% glycerol gives the best cryoprotection for quality and fertility of Indian Red Jungle Fowl semen.