Effects of increasing dietary inclusion of Moringa oleifera biomass on in vitro ruminal fermentation kinetics and degradability of lamb diets

This study evaluated the effects of increasing inclusion levels of Moringa oleifera biomass on in vitro ruminal fermentation kinetics and nutrient degradability in lamb diets. Four total mixed rations were formulated to include 0, 100, 200, and 300 g/kg dry matter of M. oleifera. Gas production kinetics, estimated metabolizable energy (ME), estimated short-chain fatty acids (SCFA) concentration, and in vitro dry matter degradability (IVDMD) were determined using the in vitro gas production technique, while fiber degradability was assessed at 24 and 48 h using the ANKOM system. Increasing inclusion of M. oleifera significantly reduced asymptotic gas production, ME, SCFA concentration, and IVDMD (p < 0.01), while the rate of gas production increased (p < 0.01); the lag phase was not affected (p > 0.05). Neutral detergent fiber degradability decreased at 24 h (p = 0.0417), with no differences at 48 h. These results indicate that higher inclusion levels of M. oleifera biomass were associated with greater reductions in several in vitro fermentation variables. These responses may be associated with changes in substrate composition and/or the presence of secondary metabolites in M. oleifera biomass. Lower inclusion levels resulted in less pronounced reductions in fermentation variables than higher inclusion levels. Further in vivo studies are required to determine the nutritional and productive implications of these responses in lambs.