**Abstract**

Globally agricultural production system generates a substantial proportion of postharvest waste that causes environmental pollution resulting in economic losses and human health-related problems. It is therefore important to make an assessment of this loss and turn it back to the consumption cycle. Processing and conversion of by-products, residues, and agricultural wastes and their reuse in the production cycle is a suitable solution for the economic use of these types of postharvest waste, especially in feeding livestock animals or in related industries. This chapter provides an overview of the assessment of the postharvest wastes that are generated in the field or on the farm at the time of harvest or processing industry. After introducing the potential use of technologies to upgrade postharvest waste for animal feed purposes and briefly discussing livestock performance, this review presents the latest and most interesting research on the use of postharvest wastes as feed.

**Keywords:** plant by-product, postharvest waste, technology, animal feed, livestock performance
