Fermentative quality and methane production in corn stover silage with fermented and unfermented nopal cactus

The objetive of this research was to evaluate the nutritive and fermentative quality and methane emissions in corn stover silages with nopal (Opuntia ficus-indica), for which three experimental treatments were evaluated, T1: corn fodder; T2: 75 % corn stover + 25 % nopal; and T3: 75 % corn stover + 25 % fermented nopal. Twenty-one micro-silos (7 per treatment) were prepared in plastic containers and left to ferment for 30 days. At the end of fermentation, the chemical composition, fermentation parameters, gas production and methane (CH4) were evaluated. Dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents were different among treatments (p<0.05); CP content increased 44 % with the addition of fermented cactus (T3). Ammonia nitrogen, lactic acid and volatile fatty acids values were different among treatments (p<0.05). Maximum gas production (Gmax) and CH4 concentration decreased 32 % and 49 % at T3, respectively. The addition of cactus and fermented cactus to corn stover silage increases protein content. In addition, it reduces ruminal methane synthesis in vitro.