Jodie Vaughan, Gavin Stewart

Beef and dairy cattle of temperate farming systems will be studied to investigate the relationships between their methane emissions as well as their efficiencies as milk and beef producers. The investigation will comprehensively utilise all research published on this topic to date via a formalised rapid review and analysing it together through a network meta-analysis. The use of organic versus conventional farming systems, the amount of time cattle spend grazing, the components of their diets and their breed as categorised by physical size will also be investigated for their effects on efficiencies and methane emissions. The bigger picture of subsequent implications on biodiversity, ecosystem services, welfare and cultural values will also be theoretically explored, as to address the often-speculated and assumed benefits of various practices such as the uses of native livestock breeds and organic farming.