Abstract
This study evaluates the effect of 22 crude ethanolic plant extracts on in vitro rumen fermentation of Themeda triandra hay using monensin sodium as a positive control. The experiment was run independently three times at 16 and 48 h of incubation periods using the in vitro gas production techniques. Fermentation parameters were determined at both hours of incubation. Plant extracts influenced gas production (GP) in a varied way relative to control at both hours of incubation, and GP is consistently highly significant (p < 0.0001) at 16 and 48 h. Microbial protein yield (MY) was not significantly affected at 16 h (p > 0.05), but it was at 48 h (p < 0.01). Higher MY was recorded for all treatments except for A. sativum and C. intybus at the early incubation stage (16 h) relative to 48 h of incubation. Compared to the control group at 48 h, all plant extracts have higher MY. After 48 h of incubation, the result shows that plant extracts have an effect on fermentation parameters determined; ruminal feed degradation, gas production, microbial protein yield, and partitioning factor in varied manners. All the plant extracts improve the MY which is the major source of amino acids to ruminants and has significant importance to animal performance. C. illinoinensis, C. japonica, M. nigra, P. americana, C. papaya, and A. nilotica (pods) were the most promising plant extracts, but further study is recommended to validate the in vitro observation in vivo.