Abstract/Summary

Food loss and waste (FLW) has become a significant issue for mitigating environmental impacts in the food system. The global food system contributes substantially to climate change, eutrophication, and other environmental concerns, predominantly attributable to the rearing and processing of animal products. Despite these concerns, chicken production is increasing worldwide and is a key focal point for mitigating greenhouse gas emissions. However, in many countries, high-nutritional value chicken co-products such as feet, giblets, and other offal are still undervalued, often considered waste and sent for valorisation rather than being consumed, leading to a limited understanding within the literature of their environmental implications. Life Cycle Assessment (LCA) studies in the agri-food sector typically allocate environmental burdens between main products and co-products based on economic value, resulting in a lower burden for chicken co-products due to their lower price compared to carcass meat. This study conducts an LCA on a typical tonne of chicken co-products in the UK to evaluate the environmental burdens of different treatment scenarios and analyse the impact of different allocation methods. It compares the current treatment with four scenarios: sending all to pet food, rendering, incineration, or anaerobic digestion, using system expansion to assess the influence of avoided products. Results show that economic allocation based on raw material price is on average 122 % lower than mass allocation, with the difference of global warming reaching 184 %, equivalent to 1953 kg CO2 eq/tonne. Processing all co-products into pet food is the most environmentally friendly option, while incineration generates the largest impact. Outcomes under system expansion are highly sensitive to the choice of displaced products, with soybean meal and palm oil substitution yielding the greatest benefits. The findings highlight the overlooked role of edible co-products in sustainable food system. However, the “pet food only” scenario does not achieve absolute reductions, suggesting that further valorisation pathways of chicken giblets, including greater integration into human diets, warrant investigation.