Effect of Milk Type Subjected to Different Heat Treatments on Cryo-Survivability and In Vivo Fertility of Buffalo (Bubalus bubalis ) Spermatozoa in a Milk-Based Extender.

Oxidative stress is a major contributory factor to cellular damage during semen cryopreservation and results in a decreased fertilizing capacity of cryopreserved bull sperm. The inclusion of exogenous antioxidants sometimes exerts deleterious effects on sperm quality. Thus, enhancing the endogenous production of antioxidants is a requirement. This study aimed to investigate the effect of milk type heated at different temperatures on the antioxidant potential of extenders, and the subsequent post-thaw quality parameters and fertility of buffalo bull semen. Cow (C) and buffalo whole milk (B) were used separately for semen extender preparation, heated at five different temperatures ( = 90°C,  = 100°C,  = 110°C,  = 120°C,  = 130°C) for 10 minutes. Reactive sulfhydryl groups were measured in each subgroup by Ellman's reagents as CT = 143.2 μM, CT = 147.4 μM, CT = 151.5 μM, CT = 157.2 μM, CT = 161.8 μM, BT = 168.3 μM, BT = 172.5 μM, BT = 176.7 μM, BT = 196.3 μM, and BT = 205.7 μM. All semen samples were cryopreserved in milk-based extenders by using standard procedures. Post-thaw quality parameters including total and progressive motility, mitochondrial membrane potential, plasma membrane integrity, and acrosome integrity were found to be higher ( < 0.05) in the group (BT) containing buffalo milk heated at 110°C, whereas in the same group, lipid peroxidation was found to be lower ( < 0.05) as compared with other treatment groups and control group. fertility of cryopreserved buffalo sperm was compared among BT, CT (conventionally used milk extender), and a Tris egg yolk extender group. The fertility rates [47% (54/114), 30% (33/108), and 36% (37/103)] were higher ( < 0.05) in BT as compared with other groups. This study suggests that buffalo milk heated at 110°C has high antioxidant potential and improves post-thaw quality and fertility of cryopreserved buffalo bull semen.