Enhancement of Ram Sperm Quality During Chilled Storage by Supplementation With Spirulina platensis Extract

This study investigated the effects of Spirulina extract, a rich source of bioactive antioxidants, on ram sperm quality during liquid storage. Semen from four mature Lori rams was collected, diluted with a Tris-based extender supplemented with Spirulina extract at concentrations of 0, 10, 20, 30, 40, 50, or 60 μg/mL, and stored at 4°C-5°C. Sperm quality parameters, including motility, viability, plasma membrane integrity, morphology, malondialdehyde (MDA) levels, and antioxidant enzyme activities, were evaluated at 1, 24, 48, 72, and 96 h. A completely randomized design with repeated measures was used, and treatment means were compared using Tukey's HSD test. The 30 μg/mL Spirulina extract (Spir-30) significantly improved total motility (74.17% vs. 63.35% in control, p < 0.05), progressive motility, linearity (28.49%, p < 0.05), straight-line velocity (VSL), and average path velocity (VAP) compared to the control and other concentrations. Plasma membrane integrity was significantly enhanced in Spir-30 (78.77% vs. 58.34% in control, p < 0.05). Additionally, Spir-30 reduced MDA levels (5.32 nmol/mL vs. 7.87 nmol/mL in control, p < 0.05) and increased glutathione peroxidase (GP_X) activity (21.35 U/mg vs. 9.28 U/mg in control, p < 0.05) and total antioxidant capacity (TAC; 4.5 mmol/L vs. 3.14 mmol/L in control, p < 0.05). These findings indicate that 30 μg/mL Spirulina extract optimally preserves ram sperm quality during refrigerated storage by enhancing motility, membrane integrity, and antioxidant defences while reducing lipid peroxidation, offering a promising supplement for improving semen longevity in Lori breed reproductive programs.