Fermentative and microbiological profile of marandu-grass ensiled with citrus pulp pellets

Abstract

High-wet roughages with low content of soluble carbohydrates, such as tropical grasses, should be inappropriate for producing silages of adequate quality. This study aimed to evaluate the fermentative and microbiological profiles of Marandu-grass ensilaged with pelleted citric pulp (PCP). Brachiaria brizantha (Hochst ex. A. Rich) Stapf cv. Marandu with 58 days of vegetative growth was harvested for producing experimental silages in PVC silos provided with Bünsen valves and density capacity of 900 kg m-3. Treatments were three PCP levels (0, 50 and 100 g kg-1 of fresh forage) and seven times (1, 4, 7, 14, 21, 28 and 56 days) after sealing. PCP inclusion increased soluble carbohydrate concentrations by 15 to 20% and reduced pH (5.3 to 4.2) and N-NH3 levels of experimental silages. An increase of the population size of the enterobacterium (mean of 3 CFU g-1) was observed only at the first day of fermentation, small growth (mean 0.5 of CFU g-1) of clostridium and the dominance of homo in relation to hetero-fermentative bacteria. Citric pulp addition during Marandu-grass ensilage was benefic, its utilization being recommended, especially when associated with economical advantages.