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 CO 2 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.