Abstract

Boar spermatozoa contain polyunsaturated fatty acids, rendering them susceptible to damage from free radicals. Oxidative stress in liquid semen can be prevented by modifying the diluent by adding antioxidants. Melatonin is an indoleamine compound that can be used as an antioxidant with high potential in the reproductive system. This study aimed to determine the effect of adding various concentrations of melatonin to Beltsville Thawing Solution (BTS) diluent on the quality of Berkshire boar semen. A Completely Randomized Design (CRD) method was employed, with the experiment divided into four treatment groups, each replicated six times. A total of 24 samples were used in this study. P0 was used as the control group, while groups P1, P2, and P3 were given the addition of melatonin to BTS diluent with different doses, namely 0.5 mM, 1.0 mM, and 1.5 mM. The samples were stored for 48 hours and then examined for boar semen quality. The variables examined included the percentage of motility, abnormality, viability, plasma membrane integrity, and malondialdehyde (MDA) levels. The results showed that the addition of a melatonin dose of 1.0 mM to the BTS diluent was the optimal concentration that could maintain motility, abnormalities, viability, plasma membrane integrity, and MDA levels in Berkshire boar semen compared to other treatment groups and the control group. This study indicated that melatonin functions as an effective antioxidant, neutralizing free radicals and thereby inhibiting oxidative stress in Berkshire boar semen.