This research aimed to evaluate the effect of Kelor (Moringa oleifera Lamm) leaf powder substitution as feed concentrate on the sexual behaviors and semen production of Kacang bucks. This research was conducted in a randomized factorial design with 2 factors, which were Kelor leaf powder substitution levels (0; 10; 20 and 30% in concentrate) and feeding periods (0; 60; 70; 80 and 90 days) with 4 replications for each combination of treatment. All data were analysed with variance analysis and followed by Duncan’s multiple range test to determine significant differences. The results showed that substitution level of Kelor leaf powder had a highly significant effect (P<0.01) to reaction time (libido), false mounting, and ejaculation time. Furthermore, a significant effect (P<0.05) was also shown to influence the erection quality but had a non-significant effect (P>0.05) on clamping and thrusting force, as well as semen production. The feeding periods had a highly significant effect (P<0.01) to reaction time (libido), ejaculation time, clamping force, erection quality, semen production and also showed a significant effect (P<0.05) on false mounting and thrusting force. The interaction of treatments in this research showed a highly significant effect (P<0.01) on ejaculation time, and a significant effect (P<0.05) to clamping and thrusting force, as well as erection quality but did not affect (P>0.05) the reaction time (libido), false mounting and semen. It can be concluded that 20% Kelor leaf powders substitution level on feed concentrate could improve the sexual behavior and semen productions of Kacang bucks.
Keywords: sexual behavior, semen production, kacang buck, kelor, feed concentrates substitution.