Effects of additives and their levels of inclusion on nutritive value of silage made from elephant grass (Pennisetum purpureum)

Résumé

The experiment was conducted to determine the effects of three additives (molasses, cracked corn and corn-soybean) and inclusion levels (0, 2.5, 5, 7.5 and 10 %) on nutritive value of elephant grass (Pennistum purpureum) silage. The experimental design was a 3×5 factorial in a completely randomized design with each treatment replicated three times. Samples were obtained from Pasture Museum. Elephant grass stands at late vegetative stage were randomly selected and harvested at 7 cm stubble height. Grass was chopped into 2-3 cm length. Five hundred gram of the sample was weighed in each case; additives were added separately at the designated inclusion levels and mixed thoroughly. Materials were then tightly packed into laboratory silos compressed and sealed tightly and left for a fermentation period of 21 days. The results indicated crude protein (CP) was significantly greater (10.92%) in silage treated with corn-soybean additive compared with other additives. Crude fiber (CF) was observed to be lower in molasses treated elephant grass silage (27.74 %). Acid detergent fiber (ADF) and neutral detergent fiber (NDF) were both lower in molasses treated silage (24.76 and 43.26 % respectively). The CP was observed to increase with increased inclusion level of the additive while CF decreased. Values for digestible dry matter (DDM), dry matter intake (DMI)as a percentage of body weight and relative feed value (RFV) were greater (P<0.05) in molasses treated silage compared to corn and corn-soybean. The DDM, DMI and RFV values were higher (P<0.05) at 7.5 and 10 % inclusion levels. Significant interactions were observed between additives and inclusion levels in most parameters measured. It was concluded that molasses additive could be used in elephant grass silage during ensiling at 7.5-10 % levels of inclusion.