Genetic parameters for feed efficiency, gas emissions, oxygen consumption and wool traits in Australian Merino.

ABSTRACT.- The purpose of the present study was to estimate genetic parameters of growing globally important traits such as feed intake, residual feed intake, methane, carbon dioxide, oxygen consumption and greasy fleece weight in Uruguay. Data of three Australian Merino generations which integrate the Uruguayan National Genetic Evaluation for sheep were recorded (from 2019 to 2021). Heritabilities and genetic and phenotypic correlations were estimated for 930 animals sired by 19 rams. Results presented suggest that relevant genetic progress can be achieved in all traits (heritabilities between 0.23 and 0.41). Methane emission present moderate to high genetic correlations with the other traits (0.57-0.88). The most efficient animals will tend to consume less feed and emit less methane, without affecting wool production. The genetic correlation between wool production and the other traits were not significantly different from zero. The developing of this work will be the basis for the construction of agroecological breeding objectives