Effects of extenders and cryoprotectants on cryopreservation of Thai red junglefowl (Gallus gallus gallus) spermatozoa.

Semen cryopreservation is crucial maintain genetic diversity of avian species. Little is known about suitable extenders for post-thaw survival of spermatozoa from Thai red junglefowl (Gallus gallus gallus). Therefore, the present study aimed to compare the suitability of the modified Thai red junglefowl extender (TRJFE) for cryopreservation of Thai red junglefowl spermatozoa with other extenders, including the Schramm extender, the red junglefowl extender (RFE), and the HS1 extender, in terms of sperm viability, motility, and fertility. First, the effects of adding 6% and 9% (v/v) N,N-dimethylacetamide, N,N-dimethylformamide (DMF), or N-methyl acetamide to these extenders on the post-thaw sperm quality of pooled ejaculates from 25 male fowls. The viability of thawed sperm was assessed by using nigrosin-eosin staining and sperm motility was determined by using computer-assisted sperm analysis. Fertility was assessed by inseminating 144 laying hens. The TRJFE +6% DMF combination significantly improved post-thaw viability (64.88 ± 0.51%) and motility (68.58 ± 1.13%) of Thai red junglefowl sperm, and the semen had the highest fertility (60.97 ± 0.72%). The findings suggest that TRJFE +6% DMF is a suitable freezing medium to conserve Thai red jungle fowl genetic resources.

Effects of egg yolk and soybean lecithin on sperm quality determined by computer-assisted sperm analysis and confocal laser scanning microscope in chilled canine sperm.

The reduction of spermatozoa survival time is a major problem of canine chilled sperm for artificial insemination. The aim of the study was to improve the quality of canine chilled sperm during storage time. We therefore, evaluated the effects of eight treatments with different levels of soybean lecithin concentration (1, 3 and 5%) and egg yolk (20%) in Tris-citric-fructose or Tris-citric-fructose-mineral salts extender on chilled canine sperm quality during 10 days of storage. The sperm motility was analysed by computer-assisted sperm analysis (CASA), whereas plasma membrane integrity, acrosome membrane integrity and mitochondrial membrane potential parameters were determined using a fluorescent staining combination of propidium iodide (PI), Hoechst 33342 (H342), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) by confocal laser scanning microscope. The results showed that egg yolk was found to be better than soybean lecithin in Tris-citric-fructose or Tris-citric-fructose-mineral salts extender for maintaining the quality of chilled canine sperm within 10 days of storage (P < 0.05). Although egg yolk in Tris-citric-fructose extender could maintain the motility better than other extenders, egg yolk in Tris-citric-fructose-mineral salts extender was the highest in intact plasma membrane, intact acrosome membrane and high mitochondrial membrane potential (P < 0.05). In contrast, the sperm quality of soybean lecithin in Tris-citric-fructose-mineral salts extender was lower than that of soybean lecithin in Tris-citric-fructose extender, and soybean lecithin 1% was greater than soybean lecithin 3% and 5% in plasma membrane integrity, acrosome membrane integrity and mitochondrial membrane potential (P < 0.05). In conclusion, soybean lecithin cannot replace egg yolk in Tris-citric-fructose or Tris-citric-fructose-mineral salts extenders, and egg yolk in Tris-citric-fructose-mineral salts extender is superior to other extenders in chilling canine sperm.