Vol. 10, Issue 3, Part E (2025)

Author(s): MV Gopala Krishna, K Venkata Ramana, E Sunil Anand Kumar, K Padmaja and D Madhuri

Abstract: Preserving liquid semen at refrigeration temperatures offers a practical alternative to cryopreservation for artificial insemination (AI) in rams, but extended storage induces oxidative stress that deteriorates semen quality. This study evaluated the efficacy of antioxidant supplementation catalase (3 mM/mL), melatonin (3 mM/mL) and methionine (4 mM/mL) in maintaining the quality of Deccani ram semen stored at 5°C. Semen was collected from six Deccani rams, pooled and diluted with an egg yolk citrate extender to a concentration of 500 10⁶/mL. Samples were allocated into four groups (catalase, melatonin, methionine and control) and stored for 0, 24, 48 and 72 hours. Sperm quality was assessed using standard microscopic techniques to determine percentage of spermatozoa individual motility, viability, sperm abnormalities, hypo-osmotic swelling test (HOST) reactivity, acrosomal integrity and DNA integrity. Results revealed that antioxidant supplementation significantly enhanced semen parameters compared to control (p≤0.05). Notably, the methionine treated group consistently exhibited superior preservation of sperm quality, with individual motility at 0 h reaching 91.67±0.80% versus 76.67±1.44% in controls and spermatozoa viability of 85.33±1.42% compared to 65.33±1.14%. These benefits persisted throughout the storage period, with methionine markedly reducing sperm abnormalities and maintaining membrane functionality and DNA integrity. Overall, the findings suggest that methionine is an effective antioxidant for preserving the functional and structural integrity of Deccani ram semen during refrigeration at 5°C up to 72 hours, offering a promising strategy to improve AI outcomes and support the conservation of indigenous sheep genetics.