# Characterization and Schematic Modeling of Oxidized Fat Use in Swine Feeding: Metabolic and Productive Consequences—A Review

## TL;DR

This review explores how using oxidized fats in pig diets can harm growth and meat quality, despite cost savings, and suggests strategies to reduce negative effects.

## Contribution

The paper provides a comprehensive review of the metabolic and productive consequences of oxidized fats in swine feeding.

## Key findings

- Oxidized fats impair digestion, energy metabolism, and oxidative balance in pigs.
- Use of oxidized fats can reduce growth efficiency and meat quality.
- Nutritional strategies are needed to mitigate the negative impacts of oxidized fats.

## Abstract

Dietary fats are commonly used in pig nutrition to increase energy intake and feed efficiency. However, the use of oxidized fats has become more frequent due to economic constraints. Oxidation products formed during fat deterioration can impair digestion, energy metabolism, and oxidative balance, leading to reduced growth efficiency and poorer meat quality. This review summarizes current evidence on the metabolic and physiological effects of oxidized fats in pigs and highlights the importance of controlling lipid quality and implementing nutritional strategies to minimize their negative impact on swine production.

Lipid sources are essential components in modern swine nutrition, not only due to their high energy density but also because of their positive effects on palatability, feed efficiency, and micronutrient absorption. However, rising raw material costs have encouraged the use of oxidized fats and oils (OxFO) as a cost-effective alternative in pig diets. These lipids, degraded by thermal and handling factors, undergo chemical alterations that negatively affect digestibility, energy metabolism, and animal health. This review critically examines the current scientific evidence regarding the impact of oxidized fat consumption in swine production systems. The physiological and biochemical mechanisms by which lipid oxidation products impair mitochondrial β-oxidation, cellular oxidative balance, energy efficiency, and meat quality are discussed. Moreover, the practical consequences on productive performance, muscle oxidative stability, and the expression of inflammatory and antioxidant markers are explored. Findings suggest that although the use of oxidized fats may offer economic savings, their metabolic and productive repercussions can compromise profitability and sustainability. The need to define safe inclusion thresholds (when replacement is not feasible), standardize analytical methods to assess oxidation status, and consider nutritional alternatives to mitigate adverse effects is emphasized.