Feed Additives Association For The Rumen Fermentation Manipulation And Reduce Production Methane In Nellore Cattle

Abstract Aimed to evaluate the association between essential oils (Next Enhance 300®), exogenous enzymes (Allzyme SSF®), and monensin for the rumen fermentation manipulation, especially reduction of rumen methane in Nellore cattle. Eight cows weighing 480 ± 55 kg and cannulated in the rumen were used in two 4x4 Latin squares, into a 2x2x2 factorial arrangement, which one of the factors being analyzed by the squared effect. The animals fed the same basal diet using a corn silage: concentrate ratio of 60:40. The factors used were: 300 mg/animal/d, 10 g/animal/d, 300 mg/animal/d for essential oils, exogenous enzyme, and monensin, respectively. Each experimental period lasted 26 days. Sixteen days were used for adaptation to the experimental diets, while from D16 to D21 for evaluation of DMI and D22 to evaluate rumen fermentation (0, 3, 6, 9, and 12h after feeding) through the ex situ technique, which consists of incubating ruminal content in conditions similar to those of the rumen allowing the measurement of rumen production (SCFA and methane). Differences were considered significant when P-value was below 0,05 through analysis of variance using mixed procedure. No significant difference (P > 0.05) was observed for DMI Monensin decreased (P < 0.05) the concentration of acetic, butyric and total SCFA. However, the production of acetic acid, propionic acid, total SCFA and acetate:propionate ratio was not altered (P > 0,05). Significant interaction (P < 0.05) between enzyme and monensin was observed for butyric acid production, indicating the enzyme used alone did not alter the production of these acid, but when associated with monensin, a reduction was observed. The enzyme reduced (P < 0.05) methane concentration, and when associated with monensin this reduction was increased. However methane production was not affected (P > 0.05). The feed additives evaluated do not reduce the rumen production of methane, but reduced butyric acid production.