Effect of Additives, Storage Temperature and Regional Difference of Ensiling on the Fermentation Quality of Napier Grass (Pennisetum purpureum Schum.) Silage

Abstract

The effects of addition of cellulases (A cremonium cellulolyticus and Trichoderma viride, CE), a commercial inoculum containing lactic acid bacteria (Lactobacillus casei, LAB), fermented green juice (macerated napier grass with water was incubated anaerobically with 2% glucose for 1 day, FGJ) and glucose (G), and regional difference of ensiling on napier grass (Pennisetum purpureum Schum.) silage were studied by using 900 ml laboratory glass bottle silos under 30 and 40°C storage conditions in 1995 and 1996. Experiment 1 was carried out to compare the addition of CE, LAB, FGJ and the combinations. Silages were stored for 45 days after ensiling. Experiment 2 studied the effects of applications of CE, LAB, FGJ and G. Experiment 3 was carried out using the similar additives as experiment 2 except for LAB. Silages were stored for 60 days in the experiments 2 and 3. Experiments 1 and 2 were done in Nagoya, and experiment 3 in Okinawa. Sugar addition through CE or G improved the fermentation quality in all the experiments, which resulted in a greater decrease in the pH value and an increased level of lactic acid, while butyric acid contents increased under 30°C storage condition in CE addition. LAB and FGJ additions hardly affected the silage fermentation quality without additional fermentable carbohydrate. But the combination of LAB, FGJ and glucidic addition (CE and G) improved the fermentation quality. The effect of the regional difference of ensiling between temperate (Nagoya; 35°N) and subtropical (Okinawa; 26.5°N) zones on silage fermentation quality was not shown in the present study.