Effect of Different Antioxidant Sources Added to Buffalo Semen Extender During Cryopreservation on Freezability and Fertility of Buffalo Spermatozoa

| There are several types of antioxidants which can be use in buffalo semen preservation. The current study was performed to study the influence of antioxidants viz., Coenzyme Q10 (CoQ10), L-Carnitine (LC), or N-Acetyl-Cysteine (NAC) added to the extender of buffalo semen on freezability and fertility of spermatozoa. Semen of Egyptian buffalo bulls (n=5) were pooled and extended with tris (1:10) without addition of antioxidant (E1), or with antioxidants i.e., 0.03 mM CoQ10 (E2), 3.0 mM LC (E3), and 1.0 mM NAC (E4). Then the diluted semen was frozen at -196oC in liquid nitrogen. Results showed that the progressive motility, livability, membrane integrity, and head-head agglutination percentages increased, while sperm abnormality and acrosomal damage decreased by all antioxidant supplements (P<0.05), being the best for E2. Pregnancy rate was higher (P<0.05) for buffalo cows inseminated with semen of E2 and E4 (81.8% for each) versus 72.7 and 63.6% for E3 and E1, respectively. In conclusion, tris-egg yolk extender supplemented with 0.03 mM CoQ10 can improve sperm characteristics of cryopreserved semen and increase pregnancy rate of inseminated buffalo cows.