The trade-off between feed efficiency, methane production and reproduction in sheep

Summary

Selecting sheep that eat less and are more feed efficient will decrease methane and carbon dioxide. Carbon dioxide can be used as an indicator trait for intake because they are closely correlated and carbon dioxide has a strong heritability. Also, there is high repeatability between ages so sheep can be selected to eat less, produce less methane and be more feed efficient younger. This means that intake can be measured cheap and fast making it a viable option for commercial breeders. Also, the most efficient and environmentally friendly animals can be selected early. This is important because sheep can be made efficient faster. For Australian agriculture it will change the way farmers think about breeding for resilience and efficiency with many new opportunities. It is difficult to breed fast growing sheep without increasing intake and methane but it's easier to breed sheep that are feed efficient and grow fast. Wool and reproduction can be improved without effecting methane and intake. Therefore, farmers can improve production and efficiency simultaneously. Finally, methane produced per kg of product can be decreased by selecting more productive sheep.