EFFECT OF FEED ADITIVES ON MICROBIAL DIVERSITY AND FERMENTATIVE ACTIVITY IN THE RUMEN OF NELLORE COWS

The ruminant production has been criticized because of the emission of Greenhouse Gases (GHG), since through the digestive process of cattle, occurs the production of methane (CH4), a strong global warming gas. Due to this, the aimed of this study was to evaluate the individually and combine use of monensin, tannins of Acacia mearnsii extract and calcium nitrate on rumen bacterial and archaeal community of Nellore cows. Five cannulated Nellore cows, non-pregnant and non-lactating, were distributed into a 5 x 5 Latin square (25 experimental units). The animals were fed with a basal diet, concentrate: roughage (corn silage) ratio of 60:40, through which the additives were supplied totaling five treatments: control (without addition of additives), monensin (300 mg in the diet), tannin (1.5 percent of DM), nitrate (3.0 percent of DM), and Pool (combination of the doses of the three additives). The rumen content (mass and liquid) of each cow was sampled for archaea and bacteria DNA extraction to evaluate the influence of microbiome in enteric methane production as well VFA and rumen nitrogen ammonia.