# Nutritional Composition and Digestibility of Corn Ethanol Coproducts in Swine Feed: A Systematic Literature Review

## TL;DR

This paper reviews the nutritional content and digestibility of corn ethanol byproducts used in pig feed, highlighting their variability and impact on swine nutrition.

## Contribution

The study provides an updated systematic review of corn ethanol coproducts' composition and digestibility in swine diets.

## Key findings

- Corn DDGS has higher crude fiber and NDF levels compared to wheat DDGS.
- Corn DDGS provides the highest digestible and metabolizable energy values.
- Amino acid digestibility coefficients in corn DDGS are generally higher than other sources.

## Abstract

The objective of this study was to conduct a literature review on the composition of ethanol coproducts and their effects on pig digestibility. The raw materials most frequently used for dried distillers’ grains with solubles (DDGS) production were corn (n = 359), wheat (n = 32), and sorghum (n = 15), whereas only corn was used for the production of high protein distillers’ grains (HPDDGs) (n = 31) and high protein distillers’ grains with solubles (HPDDGS) (n = 14). The composition of the corn ethanol coproducts varied over the analyzed years. The data provide a broad analysis of the variability in the composition and energy values of the coproducts, as well as their digestibility. The collected data reinforce the importance of considering the high variability of corn ethanol coproducts in pig diet formulation.

Corn ethanol coproducts contain high concentrations of protein, lipids, and fiber; however, their nutritional composition and digestibility vary significantly across manufacturing processes. This study aimed to survey and synthesize literature data on corn ethanol coproducts and their effects on pig digestibility. A systematic search was conducted between August 2023 and October 2025 across databases, including Periódicos Capes, ScienceDirect, Web of Science, Scielo, and Google Scholar. The search targeted publications from 2010–2005 using keywords related to DDGS, pigs, energy, and amino acids. Among the 177 articles meeting the inclusion criteria, corn DDGS was the most common coproduct (359 observations), followed by wheat and sorghum. The results indicated that wheat DDGS had the highest protein and phosphorus contents, whereas corn DDGS presented higher crude fiber and NDF levels. Furthermore, corn DDGS provided the highest digestible and metabolizable energy values, with amino acid digestibility coefficients generally surpassing those of other sources. This updated database serves as a vital tool for improving the predictability of these ingredients in swine nutrition.