EFFECTS OF SELENIUM AND α-TOCOPHEROL ON QUALITY AND FERTILISING ABILITY OF SPERMATOZOA IN EXTENDED COCK SEMEN

Spermatozoon apoptosis in extended semen is a challenge to artificial insemination in poultry production. Chicken spermatozoa undergo damages in vitro due to lipid peroxidation among other factors. Extender supplementation with exogenous antioxidants could mitigate lipid peroxidation and improve semen quality. However, inclusion of antioxidants such as selenium and α-tocopherol in semen extender to improve quality of sperm cells has not been adequately documented. Therefore, effects of selenium and α- tocopherol on quality and fertilising ability of spermatozoa in extended cock semen were assessed. Semen samples were collected from fifteen Lohmann breeder cocks aged 30 weeks, pooled and divided into nine groups. Each group was extended with Ringers Solution (RS) without antioxidant (T1), RS with α-tocopherol at 25 (T2), 50 (T3), 75 (T4) or 100µgmL -1 (T5) and selenium at 25 (T6), 50 (T7), 75 (T8) or 100µgmL -1 (T9). Another set of semen was harvested, pooled and extended with RS (TA), RS+25µgmL -1 α- tocopherol (TB), RS+25µgmL -1 selenium (TC), RS+12.5µgmL -1 α-tocopherol+12.5µgmL - 1 selenium (TD), RS+25µgmL -1 selenium+25µgmL -1 α-tocopherol (TE) were assessed in vitro and in vivo. All treatments were evaluated at room temperature (RT: 27-29 ᵒC) and refrigeration (4-6 ᵒC) at interval of 3h until motility dropped below 50%. Spermatozoa Progressive Motility (SPM), Spermatozoa Liveability (SL), Total Antioxidant Capacity (TAC, mmol/L) and Lipid Peroxidation (LP, MMDA/l0 6 Spermatozoa) were determined using standard procedures. Seventy-five Lohmann breeder hens aged 40 weeks were divided into five groups and inseminated with each of the treatments under RT and another seventy-five under refrigeration for the in vivo evaluation. Egg fertility and hatchability were recorded weekly for four weeks. Data were analysed using descriptive statistics, correlation and ANOVA at α0.05. At RT, the highest SPM (91.7±1.1%) and SL (94.5±1.0%) at 3h were recorded in T5 and least at T7 (78.3±1.1%) and T9 (83.2±1.0%), respectively. The TAC ranged from 2.0±0.14 (T9) to 3.2±0.14 (T5), while LP ranged from 0.5±0.28 (T1) to 2.8±0.28 (T7).