Environmental and welfare consequences of feeding circular feed ingredients to pigs in Ireland

Animal feed in current livestock farming systems mainly comprises of human-edible products, such as grains, which are grown on limited arable land. Among livestock, monogastric animals (poultry, pigs) have the highest proportion of grains in their diet. Using arable land to produce feed for livestock instead of food for a rising human population results in feed-food competition. This competition will continue to grow unless necessary steps are taken to minimize it. Livestock should be fed human-inedible feedstuff like leftovers and food waste (circular feed ingredients or CFIs) to reduce the dependence on global arable land to produce animal feed. CFIs can be obtained from various stages of food production but it is unclear as to which food losses or by-products could qualify as CFIs. Furthermore, the impact of feeding mainly CFIs to animals on their welfare and growth is largely unknown. Pigs are the preferred animal for investigating this impact as they are efficient at converting leftovers and currently have a diet largely consisting of human-edible feedstuff. Moreover, pig feed is a major component of pig production costs in Ireland as most feed ingredients are imported and including CFIs in pig feed might help in reducing costs. The aim of this PhD project, therefore, is to evaluate the environmental and welfare consequences of feeding CFIs to pigs in Ireland. For this potential CFIs in Ireland will be identified and different CFI based diets will be tested in an Irish pig farm setting. The diets will be investigated for their effects on the growth and welfare of Irish pigs. Next, a modelling study, informed with results from experiments, will be used to explore the opportunities of a CFI based pork production in Ireland.