Fermentative characteristics of coffee pulp silage with different proportions of coffee hulls

This study aimed to evaluate the chemical composition and fermentation characteristics of the coffee pulp silages with different proportions of coffee hulls. The material was ensiled in PVC with 150 mm diameter by 750 mm high, according to the treatments: coffee pulp (CoP), CoP + 20% of coffee hulls (CH), CoP + 40% of CH and CoP + 60% CH in a completely randomized design with six replications. The silos were opened 60 days after closing, when samples were taken for determination of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, cellulose, pH, N-NH<span style="vertical-align: sub;">3</span>, caffeine, calcium (Ca), phosphorus (P) and <span style="font-style: italic;">in vitro</span> digestibility of dry matter. We also determined gas production and effluent. There was a linear increase in DM content and pH, and a linear decrease of CP, NDF and ADF, lignin, cellulose, caffeine, Ca and P. This reduction occurs because the coffee hulls have lower levels than pulp to CP, NDF, ADF, caffeine, Ca and P. There was also a linear reduction in N-NH<span style="vertical-align: sub;">3</span> values, and only the highest percentage of silage with coffee hulls obtained below 10%, considered as the limit for good quality silage. Effluent production was higher for silage shelled coffee pulp and do not get any production in silage with 60% coffee hull. There was no significant difference in vitro digestibility of dry matter among treatments. The coffee hulls was effective in increasing DM content of CoP silage and to reduce NDF, ADF, N-NH3, providing nutritional value of silage satisfactory for cattle feed, creating an alternative for recovery of such waste. When considering the DM content found in silages, the amount of bark best coffee to be added to coffee pulp for the production of silage is between 30% and 35%.