The effects of increasing levels of citrus pulp on fermentation pattern and nutritive value of elephantgrass silage was evaluated. Elephantgrass harvested at 90 days was ensiled with increasing levels of dried citrus pulp: 0, 2.5, 5, 7.5, 10, 12.5 and 15% (fresh matter basis). Silages were produced in 28 plastic experimental silos (4 replicates/treatment) bearing Bunsen valves. Silos were opened 106 days after ensiling, when samples were taken for the analysis of silages organic acids and chemical components. Silage dry matter concentration increased linearly with level of citrus pulp. The same effect was observed for the water soluble carbohydrate concentration and the "in vitro" dry matter digestibility. However, ammoniacal nitrogen and neutral detergent fiber levels decreased linearly with citrus pulp addition. The response was quadratic for organic acids (acetic, lactic and butyric) and ethanol. The maximum point for lactic acid was observed with 5.8% and the minimal point for acetic, butyric and ethanol was observed with 7.8%, 7.2% and - 3.7% of citrus pulp inclusion, respectively. Citrus pulp did influence neither pH, nor lignin and propionic acid levels. Inclusions of 4.7 to 7.6% of citrus pulp (fresh matter basis) are enough to improve the elephantgrass silage quality.
organic acids; ensiling; fermentation; Pennisetum purpureum; orange pulp
