Associative effects of a mixed Brachiaria decumbens and Pennisetum purpureum grass feed on the ensiling properties

Abstract

This study aimed to evaluate the effects of the association between two tropical grasses, Signal grass (Brachiaria decumbens) and Napier grass (Pennisetum purpureum) on the proximate composition, in vitro digestibility, and fermentation characteristics of ensiled material. A complete randomized design was used on three treatments namely Signal grass, Napier grass, and Signal-Napier grass combination. Silage was made using molasses applied in proportions of 1:2 with water and mixed with silage at the rate of 5% for a 5kg bag of 2.5cm cut grass. Signal-Napier grass combination silage was superior in almost all parameters to the two sole crop silages. After ensiling, a significant difference (p<0.05) in most parameters was recorded. A significant difference (p=0.0004) in pH was determined where pH was lower in the sole Napier grass silage than that of the Signal-Napier combination and Signal grass. A similar outcome (P<0.05) was recorded for crude protein, ash, ether extracts, nitrogen-free extracts, and neutral detergent fiber. However, no significant difference (p>0.05) was obtained in dry matter (p=0.1524), crude fiber (p=0.5924), and ADF (p=0.1168). Although having poor digestibility values in all treatments, Signal grass proved to be better than the rest. Organoleptic characteristics were promising, with normal color, smell, and texture changes observed. These results indicated that the association of grasses had an impressive positive effect on the nutritional value and quality of silages. Therefore, the use of mixed grass silages is encouraged.