Assessment of different phytogenic-based additives onrumen fermentation profile and methane emissions.

Abstract

INTRODUCTION: Phytogenic feed additives have gained increasing attention in ruminant nutrition due to their capacity to modulate ruminal fermentation and reduce methane (CH) emissions. This study evaluated the effects of three plant-based additives. METHODS: Neem leaf (; NL), Indigofera leaf (; IL), and Pumpkin peel (; PP) included at four levels (0, 10, 20, and 30&#x202f;g/kg DM) onruminal fermentation, feed degradability, and CHemissions. A total mixed ration (TMR) was incubated with each additive and buffered rumen fluid using thegas production technique for 24 hours. RESULTS AND DISCUSSION: NL and IL supplementation significantly (<&#x202f;0.05) increased gas and carbon dioxide (CO) production, organic matter degradability, and total volatile fatty acid concentrations, particularly propionate and butyrate. Simultaneously, acetate concentration, CHemissions, NH-N levels, and protozoa abundance were reduced (<&#x202f;0.05). However, PP had limited effects on these parameters. The phenolic profiles of NL and IL, notably rich in 2-hydroxycinnamic acid and p-coumaric acid, likely contributed to these outcomes. In conclusion, these findings support the use of NL and IL as effective phytogenic additives for improving rumen fermentation and mitigating CHproduction. Furthertrials are recommended to validate theseresults.