Effect of supplementation with tree foliage on in vitro digestibility and fermentation, synthesis of microbial biomass and methane production of cattle diets

Abstract

The main task was to evaluate the effect of tree foliage species supplemented in cattle balanced diets on the in vitro fermentation and digestibility, synthesis of microbial biomass and methane (CH4) production. The experimental diets were isoenergetic and isoproteic balanced and formulated to meet the requirements of growing cattle (250 kg BW). Seven treatments were tested: control treatment (CT1) with the grass Pennisetum purpureum and six additional treatments substituting P. purpureum (30% of DM) with foliage of Neomillspaughia emarginata (NE2), Tabernaemontana amygdalifolia (TA3), Caesalpinia gaumeri (CG4), Piscidia piscipula (PP5), Leucaena leucocephala (LL6) and Havardia albicans (HA7). A randomised complete block design with blocks repeated over time was implemented. The highest gas production (P < 0.05) was found in CT1 and TA3 (244.10 and 235.13 mL g−1, respectively). The highest in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) (P < 0.05) were in CT1, TA3 and LL6 (IVDMD = 56.33%, 56.85% and 56.08%; IVOMD = 62.41%, 66.86% and 64.38%, respectively). Synthesis of microbial biomass and volatile fatty acid concentration was similar among tree foliage supplementation and CT1, and the lowest CH4 production (P < 0.05) was found in LL6 (35.94 L kg−1 of digested dry matter). It is concluded that the supplementation with T. amygdalifolia, P. piscipula and L. leucocephala at 30% in balanced diets could be used without affect negatively the organic matter digestibility of the diets, the synthesis of microbial biomass and the volatile fatty acid concentration. Additionally, the supplementation with L. leucocephala reduces CH4 production in the rumen by 12.78%.