NUTRITIVE VALUE OF NAPIER GRASS (PENNISETUM PURPUREUM SCHUM.) SILAGE ENSILED WITH MOLASSES BY GOATS

Napier grass (Pennisetum purpureum Schum.) harvested at an early growth stage was ensiled with 4% of molasses in a polyethylene bag silo which contained 15 kg of chopped forage each. Dry matter (DM) content of the silage was so low as 14.75%, although chemical quality of the silage was very high. Ratio of ammonia nitrogen to total nitrogen was 6.59%, and the pH value of the silage was 3.79. Nutritive value of the silage was estimated using goats and compared to that of a timothy hay as a reference ration. Feeding level of each rations was adjusted to a level of nitrogen (N) recommendation. DM and N digestibilities of the silage were 65.0 and 54.5%, respectively, but those of the timothy hay were 37.6 and 37.2%. Feeding of the napier grass silage maintained body weight and kept positive N retention. Ammonia N concentration in the rumen fluid in goats fed the napier grass silage increased after feeding, but blood urea concentration was constant. Feeding of the timothy hay did not increase ammonia N concentration in the rumen fluid, but increased blood urea concentration. These facts indicated that the napier grass silage had enough digestible DM and N for maintenance ration to goats.