Especificações padrões para mensurações de gases de efeito estufa e metabolismo de pequenos ruminantes no bioma Caatinga.

Resumo: A respirometria em ensaios com pequenos ruminantes contribui para a mensuracao das emissoes de gases de efeito estufa (GEE), subsidio ao pagamento por servicos ambientais e para o desenvolvimento de racoes e suplementos que propiciem a maxima eficiencia alimentar. Para as afericoes de emissao de GEE, 15 cordeiras Santa Ines, com peso de 15,09 kg±2,63 kg, foram avaliadas na câmara respirometrica do Laboratorio de Respirometria do Semiarido (Laresa) da Embrapa Caprinos e Ovinos. As dietas foram for-muladas conforme as exigencias nutricionais descritas pelo NRC (National Research Council, 2007), em planos nutricionais para manutencao, acaba-mento de carcaca precoce e de carcaca tardia, com cinco repeticoes. As taxas medias de recuperacao para CO2 e CH4 foram de 96,5% e 92,5%, res-pectivamente. Os coeficientes de variacao foram 0,73% e 0,85% para CO2e CH4. Os coeficientes de variacao dentro de animal foram 2,63% e 2,81% para as emissoes de metano em L/dia e em L/Kg de materia seca ingerida, respectivamente, e os coeficientes de variacao entre animais foram 12,1 e 11,76%, respectivamente. Para producao de calor, dentro e entre animais, os coeficientes foram 1,54% e 8,13%, respectivamente. O sistema de avaliacao de metabolismo animal e producao de gases no Laresa segue os padroes internacionais de afericao de medidas respirometricas. [Standard specifications for greenhouse gas measurements and small ruminant metabolism in Caatinga biome]. Abstract: Respirometry in trials with small ruminants contributes to the measurement of greenhouse gas (GHG) emissions, subsidies for payment for environmental services and the development of rations and supplements that provide maximum feed efficiency. For GHG emission measurements, 15 Santa Ines lambs, weighing 15.09 kg±2.63 kg, were evaluated in the respi-ratory chamber of the Embrapa Caprinos e Ovinos Semiarid Respirometry Laboratory (Laresa). The diets were formulated according to the NRC (National Research Council, 2007), in nutritional plans for maintenance, early carcass finishing and late carcass, with five repetitions. The average recovery rates for CO2 and CH4 were 96.5% and 92.5%, respectively. The coefficients of variation were 0.73% and 0.85% for CO2 and CH4. In animal coefficients of variation were 2.63% and 2.81% for methane emissions in L/day and L/Kg of ingested dry matter, respectively, and coefficients of variation between ani-mals were 12.1 and 11.76%, respectively. For heat production, within and be-tween animals, the coefficients were 1.54% and 8.13%, respectively. Laresa?s animal metabolism and gas production assessment system follows interna-tional standards for the measurement of respirometric measurements.