The paper “The net contribution of livestock to the supply of human edible protein: the case of Ireland”, published in The Journal of Agricultural Science, has been chosen as the latest Editorial Highlight and is freely available.

When discussing how we should design our future-food systems we need to consider feed-food competition occurring in our livestock systems. Feed-food competition occurs when arable land, which could be used to produce human edible food from crops, is instead used to produce feed for livestock. This can result in a net loss in the amount of food produced. Feed-food competition is problematic as we need to ensure that our agriculture sector uses the resources available as efficiently as possible to sustainably meet our global dietary demands. Quantifying the level of feed-food competition that is occurring in our livestock systems increases the understanding of the effect of the livestock system on global food supply.

Ireland serves as in interesting case study for feed-food competition. It is primarily a livestock orientated system with 90% of all land used for pasture and 75% of all crops used for feed. The livestock systems examined for feed-food competition were the ruminants dairy and its beef, suckler beef, and the monogastric pig system.

This study evaluated feed-food competition in case study livestock systems across two different metrics. The first is the protein conversion ratio (PCR) which compares feed-use efficiency of the Human Digestible protein (HDP) in the feed entering the livestock system against the HDP produced by the livestock. The second is the land-use ratio (LUR) which compares the potential crop yield that could be grown on the land used for the livestock’s feed against current livestock production. Using both these metrics, we can demonstrate feed-food competition in Ireland’s livestock system.

Our results show that there is a demonstrable level of feed-food competition in Ireland’s livestock systems. The analysis showed that the PCR while able to demonstrate how efficiently livestock can convert feed to food, could not fully demonstrate feed-food competition because it did not take into account the opportunity lost from the land. In contrast the LUR can demonstrate feed-food competition by demonstrating the opportunity cost of livestock production. As such, it’s clear that a typical Irish dairy system is producing more HDP than if the land used to produce livestock feed, if suitable were converted to crops for human food. The suckler beef and pig systems were found to be land-use inefficient and more food could be produced if the land was used for arable crops.

Feed-food competition occurred in Ireland’s pig system due to its reliance on primary crops. Removing that competition by feed the pig’s by products would change its LUR to a more land-use efficient value. Similarly suckler beef systems became more land use efficient if placed on land that was not suitable for food production. Significant land use competition occurs from the use of pasture that is suitable for crop production. Ruminants placed on marginal pasture unsuitable for conversion to arable production, results in an increase land-use efficiency.

The Journal of Agricultural Science Editorial Highlights are selected by the Editor-in-Chief and are freely available for one month. View the recent selections here.