Resumen:
Tanniferous forages, leaves and pods from legume trees can be used as feed additives to reduce enteric CH4 in tropical regions of the world where smallholder farmers cannot afford to purchase commercial anti-methanogenic feed additives. The present work aimed to evaluate the impact of small doses of Gliricidia sepium (G. sepium) alone or in combination with coffee pulp (COP) on enteric CH4 production in cattle. A 4 × 4 Latin square experimental design was used, where four Holstein x Charolais heifers of 390 ± 50 kg body weight were used. Four treatments were evaluated, with G. sepium (GSep) and COP used as additives. The control treatment (CON) had no additives and was offered ad libitum, the COP treatment contained 1.0 kg DM d−1 of COP, the treatment with G. sepium contained 0.342 kg DM d−1 of this plant, and the treatment with both plants (COP + GSep) had 0.505 and 0.171 kg DM d−1, respectively. The lowest CH4 production was observed for the COP + GSep treatment, followed by GSep, with 17% and 14.2% less CH4, respectively, compared to the CON treatment (p < 0.05). We concluded that supplementation with G. sepium, alone or in combination with COP, can be used as part of a strategy to mitigate enteric CH4 production in tropical cattle production systems. To the best of our knowledge, this is the first time two natural additives have been used together to reduce enteric methane in cattle fed a low-quality forage.