DOSE-DEPENDENT EFFECTS OF POLYHERBAL MIXTURE SUPPLEMENTATION ON METHANE MITIGATION, FERMENTATION CHARACTERISTICS, AND IN VITRO DRY MATTER DIGESTIBILITY USING THE GAS PRODUCTION TECHNIQUE

Abstract

An in vitro study was conducted to evaluate the methane mitigation potential of selected herbal mixtures containing fenugreek seeds, shikakai pods, ginger rhizomes, betel leaves, guava leaves, and turmeric rhizomes. Different herbal mixture combinations were prepared by incorporating each herb at 20, 40, 60, 80, and 100 mg levels. Each herbal combination was further evaluated at four dose levels, viz., 0.025%, 0.05%, 0.075%, and 0.1%, using the in vitro gas production technique in six replicates. Methane production, rumen fermentation characteristics, and methane production per 100 mg of truly digested substrate were assessed to determine the efficacy of the herbal mixtures in reducing enteric methane emission. The results revealed that methane production per 100 mg of truly digested substrate was significantly (P<0.05) reduced in several herbal mixture combinations compared to the control group (7.77 ml). Among the treatments, the 60 mg herbal mixture at 0.05% supplementation level exhibited the lowest methane production (4.55 ml), followed by 80 mg at 0.05% (4.70 ml), 100 mg at 0.05% (4.76 ml), and 100 mg at 0.075% (4.82 ml). The findings indicate that herbal feed additives have considerable potential as natural, eco-friendly methane-mitigating agents in ruminant nutrition without adversely affecting substrate digestibility.