Ruminal fermentation characteristics and methane emissions with the addition of Cassia spp. extract to a total mixed ration based on corn stover

Abstract

This study evaluated the effects of the addition of four different Cassia species extracts to a total mixed ration (TMR) composed of corn stover on the characteristics and methane emissions in vitro. The design used was a randomized complete block design (RCBD), with the source of inoculum derived from rumen fluid taken from three sheep serving as groups in the treatment. The concentrations of Cassia siamea, C. fistula, C. surattensis, and C. spectabilis extracts added to the TMR based on corn stover were 2 mg/mL. Every treatment was repeated three times. The variables observed were in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD); microbial protein synthesis (MPS); volatile fatty acid (VFA) content; acetate, propionate, and butyrate levels; gas production; methane; and populations of methanogen bacteria and protozoa. The study showed that the addition of Cassia spp. extract to TMR at a dose of 2 mg/mL increased (P <0.05) the IVDMD, IVOMD, N-NH3, and total bacterial population but decreased the total and partial VFA, methanogenic bacteria, and the number of protozoa. The addition of C. surattensis extract reduced methane emissions by 13.11% compared with those of the controls based on the percentage of total gas or 14.9% based on mL/g DOM (P <0.05). In conclusion, Cassia spp. extract is a potential agent for reducing methanogenesis in the rumen.