Quality Assurance of Cryopreserved Buck Semen by Assessing Structural and Functional Integrity of Spermatozoa

A total of 81 ejaculates collected from 4 Tellicherry and 2 Boer bucks were utilized to evaluate the structural and functional integrity of spermatozoa as a measure for quality assurance of cryopreserved buck semen. The semen samples were diluted with tris-egg yolk-glycerol based extender and frozen in straws. Only samples having 40% or more of post thaw motility (PTM) were regarded as “acceptable” samples for artificial insemination. The “acceptable” samples were further evaluated by hypo osmotic swelling test (HOST), sperm morphology and acrosome integrity assessment. Individual genotypes have shown significant variations (P < 0.01) for PTM. Significant variations (P < 0.01) were seen between bucks and between ejaculations of two Tellicherry bucks for hypo osmotic reacted spermatozoa. The differences in mean values for hypo osmotic reacted spermatozoa between I and II ejaculations of Tellicherry bucks were significant (P < 0.01). Significant variations (P < 0.05) were also observed for hypo osmotic reacted spermatozoa between I ejaculations of Tellicherry and Boer bucks. The variations in means of intact acrosome percent between I and II ejaculations of Tellicherry bucks was significant (P < 0.05). Besides post thaw motility, incorporation of structural and functional integrity tests like HOST and acrosome integrity in semen evaluation protocol add value to quality assurance of frozen buck semen.