Potential of Fruits and Vegetable By-Products as an Alternative Feed Source for Sustainable Ruminant Nutrition and Production: A Review

The agro-food industry produces tons of waste at different stages in the food production process, creating a massive ecological crisis. If implemented, the use of fruit and vegetable by-products (FVBPs) in animal nutrition has the potential to lessen the environmental footprint of the food production chain, lower animal feeding costs, and improve the quality and sustainability of animal products. Recent research on the inclusion of FVBPs, naturally enriched with polyphenols, in the diets of small and large ruminants has shown some promising outcomes, which we discuss in this review. The effects of FVBPs on digestion, rumen fermentation, methane emissions, rumen liquor fatty acid profile, and milk production are examined. Due to the chemical composition and the presence of certain bioactive compounds, FVBPs are capable of influencing the ruminal and intestinal ecosystem through improved kinetics of fermentation. Several in vivo studies have demonstrated that the dietary inclusion of FVBPs resulted in improved milk production and composition without any negative effect on animal performance. Using FVBPs as an alternative to conventional feedstuffs may promote sustainable animal production and nutrition. However, it must be stressed that the efficacy of these feed supplements is conditional on the source, kind, and quantity employed.