Comparison of TNC and standard extender on post-thaw quality and in vivo fertility of Thai native chicken sperm.

Semen extender has a vital role in preservation of sperm cells properties in terms of sperm viability, motility, acrosome integrity, and mitochondrial membrane potential. The objective of the present study was to evaluate a new extender, known as Thai native chicken (TNC) extender compared to BHSV-based and modified Sasaki extenders for freezing chicken semen. Semen from Thai native roosters was collected, pooled, and randomly divided into three groups. Semen was frozen with a simple freezing method using nitrogen vapor and dimethylformamide. In the first experiment, post-thaw motion parameters, viability, acrosome integrity, mitochondrial function, and lipid peroxidation levels were analyzed using computer-assisted sperm analysis, propidium iodide, fluorescein isothiocyanate-conjugate peanut agglutinin, JC-1, and the thiobarbituric acid reaction. Results showed that the type of extender had no effect on the percentage of total motile and curvilinear velocity. The percentage of progressive motile, straight-line velocity, and average path velocity of post-thawed semen were significantly lower in TNC compared to the modified Sasaki extender. However, the percentages of post-thawed acrosome integrity and active mitochondria were significantly higher in TNC extender (P < 0.05). For the second experiment, semen was thawed by using each of extenders thereafter, was inseminated to 48-layer breeder hens to determine the fertility rate. Among the three extenders used, the highest fertility rate was found in TNC extender. In conclusion, TNC extender can be recommended as an appropriate and useful cryopreservation media for native chicken semen since it maintains the quality of rooster semen and fertility after freezing and thawing process.