Evaluate the land-use efficiency of regional livestock systems from a food systems perspective: Davos, Switzerland, 30 August-3 September 2021

The aim of this study is to evaluate the land-use efficiency of four different livestock systems from a food systems perspective. To this end, we quantified the land-use ratio (LUR) of livestock systems in seven regions of Ireland across different soil types and climatic conditions. The LUR is a metric that quantifies the level of feed-food competition occurring in livestock systems. It compares the quantity of human digestible protein (HDP) produced by the livestock system against the HDP of the potential alternative crop from the land used to grow the system’s feed and fodder. The source of this feed may be in-situ pasture or feed imported from crop systems at a national and international level. A LUR of <1 demonstrates that the livestock system is an efficient user of its land; producing more HDP than could be grown in the alternative crop. In contrast, a LUR of >1 in a livestock system demonstrates that the system is land-use inefficient. The four livestock systems studied include three pasture-based ruminant systems: the dairy and its surplus beef calf system; a suckler beef system, a sheep-meat system, and a monogastric pig system. The different biophysical features in the regions as studied include; different pasture yields, different proportion of pasture suitable for crop systems, and different crop yields. In this study, only the dairy beef system had a LUR value <1 in every region; LUR values ranged from 0.21 to 0.71. The sheep-meat system is land-efficient in only three out of seven regions, LUR ranged from 0.52 to 2.16. The suckler beef system was land-efficient in only two out of seven regions, LUR values ranged from 0.77 to 2.78. Lastly, the pig system was not land-use efficient in any region, LUR values ranged from 1.89 to 2.00. Hence, our results demonstrate that certain regions are more suitable for ruminant systems based on their suitability for cropping and pig systems that were based human edible feed were consistently land-use inefficient.