LAUSR

BACKGROUND The in vitro gas production technique has been used to evaluate the forage fermentation kinetics. However, individual and animal species variation can change fermentation patterns due to differences in ruminal environment and microbiota. The aim was to verify if rumen inoculum (RI) of llama had superior intrinsic digestion capacity and reduced methane (CH4 ) production than sheep's RI using fescue and paspalum hay as substrates. RESULTS Dry and organic matter digestibility produced with llamas' RI tended to exceed the sheep's one (P= 0.099 and 0.074, respectively) at 24 h of incubation. However, at 48 h, the sheep's RI presented higher substrate digestibility and asymptotic value of gas production than the llama's (P< 0.010). The CH4 production showed no differences between RI or substrates (P> 0.050). The NH3 -N and total VFA concentrations were greater in the RI of llamas compared with sheep's ones (P< 0.050). Acetate and butyrate proportions and acetate to propionate ratio were greater in the RI of llamas compared with the sheep ones (P< 0.001) at 24 and 48 h. However, propionate proportion was greater in sheep compared with llamas (P< 0.001). CONCLUSION The llamas' RI tended to surpass the sheep's one in dry and organic matter digestibility at 24 h of incubation, but sheep's RI at 48 h presented a higher digestibility and gas production value than llamas' RI. No differences between both species were detected for CH4 production. This study showed that llama's RI did not perform better than sheep's one to digest low-quality forages. This article is protected by copyright. All rights reserved.