Optimizing cryopreservation of semen and artificial insemination in pigs

Abstract

A total of forty-two ejaculates from six Lumsniang crossbred boars, maintained at Livestock Research Farm. DAFS, ICAR Research complex for NEH Region, Umiam, Meghalaya were used in the present study. Semen was collected twice weekly by gloved hand method using dummy sow in a sterilized semen collection bag fitted inside the insulated collection cup. The sperm rich fraction of 42 ejaculates showing more than 70 per cent initial motility was considered for further processing and freezing. The semen parameters were assessed in fresh ejaculates, 1 hour after equilibration and during post thawed period. The extended semen with different nanoparticles, packaging systems and thawing temperatures and times were assessed for optimizing of cryopreservation. A total of 5 semen samples, including one fresh and rest four frozen with BTSLEYG extender, out of which three with ZnO-NPs, Se-NPs, Fe3O4-NPs nanoparticles and one Control (without nanoparticles) were assessed to study the ultrastructural changes of spermatozoa by scanning electron microscope and transmission electron microscope, respectively. The optimized frozen thawed boar semen with best nanoparticles, packaging methods and thawing temperatures and times was used to assess conception rate following artificial insemination in oestrus pig. The overall mean percentages of fresh boar semen evaluated for volume, pH, sperm concentration, total sperm per ejaculate, initial motility, live sperm, intact-acrosomal membrane (by Giemsa), intact plasma membrane integrity, sperm viability, acrosomal intact (by FITC-PSA), mitochondrial membrane potentiality (MMP) of spermatozoa and sperm DNA integrity revealed no significant difference between boars. The boar semen after 1 hour of equilibration in BTSLEYG extender with ZnO-NPs (10µM), Se-NPs (1.0 µg), Fe3O4-NPs (0.192 mg/ml) and without nanoparticles (Control) group showed non-significant (Plt 0.01) difference between straws, sachets and cryovials. Assessment of quality of frozen boar semen of different thawing temperatures and ti