Optimization of Trehalose Concentration in Semen Freezing Extender in Thai Native Chicken Semen
The aim of this study was to find optimal concentration of trehalose supplemented to semen extenders (0, 5, 10, and 15 mM). Ejaculates were collected from 24 Thai native cocks (Pradu Hang Dam; 1 year old), then diluted (1:3) and pooled before allocation to treatments. In the experiment, semen was either cooled to 5oC after dilution or diluted with a pre-cooled diluents before cooling to 5oC. Semen freezing was performed in liquid nitrogen vapor at -135oC and -35oC, with 6% DMF, and compared for sperm qualities. After thawing, it was measured for total sperm motility and progressive motile by CASA. Sperm parameters in terms of viability (PI), acrosome integrity (FITC-PNA), and mitochondrial function (JC-1) were evaluated using flow cytometry. Malondialdehyde concentration was assessed by TBARS for levels of lipid peroxidation and fertility test was carried out by inseminating layer hens. Results showed that the extender supplemented with 5 mM trehalose produced the greatest sperm motility, progressive motile, intact acrosome membrane, mitochondria activity and fertility rates (P<0.05).