Across-country prediction of methane emissions using rumen microbial profiles

Rumen microbial profiles have been shown to be accurate predictors of methane emissions in a variety of species, however, it can be very costly and slow to generate a dataset with a sufficient number of individuals measured for methane who also have had rumen samples collected and processed into rumen microbial profiles for these benefits to be applied in industry. We evaluated the potential of combining datasets from New Zealand and Australian sheep to improve our ability to accurately predict methane emissions in Australian sheep. Prediction of Australian sheep methane emissions using rumen microbial profiles and phenotypes from New Zealand was possible, however, it was important to closely match the diets the sheep were fed to have confidence in the predictions. Prediction accuracies of Australian sheep methane emissions were higher when training on data collected on Australian sheep than training on New Zealand sheep; however augmentation of New Zealand data collected on a similar diet enabled more complex models to be run and an improvement in prediction accuracy.