The orange peel with enzymatic microbial additive, formic or acetic acids was ensiled for 70 days, in concrete tubes with 700 kg of volume capacity, was evaluated by rumen fermentation parameters in a experimental trial using males sheep, housed in metabolic cages. The used diet was oat hay (70%) and orange silage (30%) on DM base. The ruminal fluid was collected with esophageal tube at 2, 5 and 8 hours after, and before feeding that was taken as zero time (0). The pH, N ammonia, volatile fatty acids (acetic, propionic and butyric) and the energy contribution of these acid in kcal were evaluated. There were no differences among treatments for the evaluated characteristics. The regression equations presented quadratic behavior for all studied characteristics and the averages of the characteristics were: pH, 6.97, N amoniacal, 6.78 mg/100 mL of ruminal fluid and acetic, propionic and butyric acids values of 45.99, 11.16 and 5,50 mM/mL of ruminal fluid, respectively. The additives did not alter the nutritional value of the diet when evaluated by the rumen fermentation characteristics. However, for VFA production, there was a better energy conversion efficiency (kcal of VFA/kcal of glucose), 72.92% for the control treatment (without additive).
additives; ammonia N; by-products; orange peel; ruminal pH; volatile fatty acids
