In vitro gas production, rumen fermentation and production performance of steers fed multinutritional prickly pear blocks

The aim of this study was to evaluate the replacement of oat hay exclusively with fermented prickly pear in developed multi-nutritional blocks (MNBs) on steer production efficiency and in vitro rumen fermentation parameters. Two experiments were performed: Trial 1 (in vitro assay) evaluated in vitro fermentation parameters of three MNBs replacing oat hay (MNB0 - 0% prickly pear, MNB1 - 25% prickly pear, MNB2 - 25% fermented prickly pear). Trial 2 (in vivo assay) evaluated the effect of MNBs on steer production performance. Both experiments were established as a completely randomized design. The values for proteins, metabolisable energy, gas production, methane and CO(2)were higher in MNB2 (P < 0.05) group. Total and individual volatile fatty acids differed between experimental MNBs groups (P < 0.05). Mean body weight and mean live-weight gain of steers were increased with MNB supplementation in T2 group by 12 and 37%, respectively. Dry matter digestibility was higher (P < 0.05), but methane and CO2 production in the rumen decreased with MNB supplementation (P < 0.05). Replacing 25% of oat hay with fermented prickly pear leaves increases the nutritional quality of MNB2, while improving animal production variables and reducing rumen methane emissions.