Skimmed Milk Diluent Promotes the Sperm Motility and Conception Rate of Dorper Sheep Compared to Vitamin B12 Diluent.

BACKGROUND: Dorper sheep is an ideal breed for improvement, with higher meat production and increased adaptability. Artificial insemination is an efficient technique for Dorper genetic improvement and reproduction management. However, there is no uniform diluent for Dorper semen dilution. OBJECTIVE: To compare the effects of vitamin B12 (VB12) and skimmed milk diluents on sperm motility at different ratios and time points, and the effects on conception rate. MATERIALS AND METHODS: We detected the effect of diluents on sperm density, deformity, motility and conception rate of Dorper sheep. RESULTS: We found the optimal dilution ratio of skimmed milk is 1:3. Compared to VB12, skimmed milk at 1:3 ratio prolonged semen storage time (48 h vs. 18 h, storage at a low temperature of 4°C) and increased the survival index of sperm (44.7 ± 2.8 vs. 18.5 ± 0.6, P<0.01). CONCLUSION: Skimmed milk is more effective, nutritious and convenient than vitamin B12, representing a more advantageous diluent.