Biogas production from prickly pear cactus containing diets supplemented with Moringa oleifera leaf extract for a cleaner environmental livestock production

This study presents an experimental investigation of the effect of corn grain replacement with prickly pear cactus and M. oleifera leaf extract in ruminal diets. In the control diet, 40 and 70% of corn grain was substituted with prickly pear cactus, while the level of M. oleifera leaf extract was varied from 0 to 1.8 mL/g dry matter. A significant interaction between experimental diet and dosage of M. oleifera leaf extract was observed for methane, carbon dioxide, and total gas production. An increase in the composition of pear cactus in the diet resulted in a significant decrease in carbon dioxide, methane, as well as the total gas production. A decrease in lag time of gas production was also observed. The asymptotic methane production and the rate of methane production decrease in all the diets with the increase in M. oleifera leaf extract doses. Addition of M. oleifera leaf extract to the control diet resulted in a decline in carbon dioxide production, while the reverse was the case when M. oleifera leaf extract was added to pear cactus containing diet. Therefore, replacement of corn grain with pear cactus and the addition of M. oleifera leaf extract resulted in a decrease in the production of greenhouse gases. This is a promising formulation for ecofriendly livestock diet. (C) 2018 Elsevier Ltd. All rights reserved.