Fungal bioprocessing of wheat straw with fruit and vegetable discards to produce cattle feeds for enhanced sustainability

Feed production for livestock requires abundant resources which compete with human food production. However, the food supply chain unintendedly generates a large amount of food loss and waste that impedes sustainability. This study tested the utility of making cattle feeds from wheat straw (WS) and fresh fruit and vegetable (FFV) discards through fungal bioprocessing. Two food-grade fungi, Tramates versicolor and Pleurotus ostreatus demonstrated high efficacy in degrading lignin (34–48 % and 16–29 % reduction, respectively) in fermented WS. Co-fermenting WS with FFV resulted in a large reduction of soluble nutrients from FFV, which were assimilated into fungal biomass for subsequent use in animal feed. Changes in the nitrogen profile occurred, with a decrease in nitrate and soluble proteins and increases in essential amino acids. These results demonstrate the potential for improving energy and protein value of crop residues and fruit/vegetable discards via fungal fermentation to achieve more circular food production and a more sustainable food future.