Concentrate supplementation on milk yield, methane and CO2 production in crossbred dairy cows grazing in tropical climate regions

The objective of this study was to evaluate the level concentrate supplementation on production and chemical composition milk from 12 crossbred F1 dual-purpose cows (½ Bos taurus – ½ indicus) estimate emission CH4, N2O, CO2 gases. included over 60 days lactation. grazed 28% tropical native grassland 72% Brachiaria spp. Cynodon neumfluensis, supplemented with 0, 150, 300, 450g per kg daily production, during three experimental periods 15 each in a crossover design. Pasture samples were collected analyzed for dry matter, crude protein, neutral detergent fiber, acid fiber. Milk (kg d-1) recorded daily, nitrous oxide (N2O), emissions excreta CH4 calculated. Results SAS MIXED procedure. Concentrate dairy did not improve yield but increased N2O (P < 0.0001) cow as diet; Ym factor region yielded less than IPCC model 0.0001). In conclusion, calculation using specific factors climate is better default order overestimate emissions.