Use of oxidized fats in pigs: risks and considerations

Fats and oils are essential components in pig diets. They provide energy, essential fatty acids, contribute to the sensory characteristics of feed, and influence meat quality (Chen et al., 2018).

However, when exposed to oxygen, light, and heat, fats can undergo oxidation, leading to changes in their chemical composition, flavor, and nutritional value (Nourooz-Zadeh, 1999). This directly affects the composition of the diet, animal health, productive performance, and product quality.

Since pig nutrition is a critical aspect of swine production from both production and economic perspectives, there has been growing interest in recent years in using oxidized fats as ingredients in pig diets (Chen et al., 2018).

FORMATION OF OXIDIZED FATS

Fat oxidation occurs through a complex series of chemical reactions involving the interaction of unsaturated fatty acids with oxygen molecules.

CHEMICAL CHANGES

Fat oxidation results in the formation of various chemical compounds:

• Hydroperoxides
• Aldehydes
• Ketones
• Free radicals

These compounds can alter the taste, aroma, and nutritional properties of fats, leading to unpleasant flavors, rancidity, and a reduced shelf life.

Additionally, oxidation can decrease the nutritional quality of fats by reducing levels of essential fatty acids and fat-soluble vitamins (Nourooz-Zadeh, 1999).

The use of oxidized fats in animal feed can affect feed palatability, nutrient digestibility, and productive performance.

High levels of oxidation products can compromise the nutritional quality of feed ingredients and pose health risks to animals (Cherian & Jacob, 2006).

IMPLEMENTATION OF OXIDIZED FATS IN SWINE FEEDING

The use of oxidized fats in swine diets has been a topic of controversy. The literature includes both positive and negative findings regarding their application:

Reported benefits of oxidized fats in swine feeding include:

Energy source

They can be cost-effective for pig producers, especially when fresh fat sources are expensive or in short supply. However, incorporating oxidized fats into pig diets might compromise feed nutritional quality due to the chemical changes fats undergo during oxidation.

Cost-effectiveness

They can be cost-effective for pig producers, especially when fresh fat sources are expensive or in short supply. However, incorporating oxidized fats into pig diets might compromise feed nutritional quality due to the chemical changes fats undergo during oxidation.

Reutilization

Oxidized fats, which may not be suitable for human consumption due to unpleasant flavors or rancidity, can be reused as feed ingredients for pigs. This reduces waste in the food industry and contributes to the sustainable use of resources (Gourle et al., 2020).

Risks associated with the use of oxidized fats in pig feeding include:

Nutritional implications

Oxidized fats may contain reduced levels of fat-soluble vitamins and antioxidants due to the oxidation process. Pigs fed diets rich in oxidized fats may be at risk of nutrient deficiencies, particularly vitamin E, which plays a critical role in antioxidant defense and immune function (Nguyen et al., 2019).

Palatability and digestibility

Oxidized fats can impart unpleasant flavors and odors to feed, potentially affecting its palatability and consumption by pigs. Oxidative byproducts can also hinder the digestion and absorption of fats, leading to reduced nutrient utilization and growth performance (Chen et al., 2018).

Health risks

The consumption of oxidized fats has been linked to adverse health effects in animals, including oxidative stress, inflammation, and compromised immune function. Pigs fed diets with high levels of oxidized fats may be more susceptible to oxidative damage and metabolic disorders (Jha & Berrocoso, 2016).

CONSIDERATIONS

Oxidized fats exhibit distinct characteristics resulting from the oxidation of unsaturated fatty acids.

The chemical changes during oxidation lead to the formation of volatile compounds that affect the taste, aroma, and nutritional properties of fats.

Understanding the characteristics of oxidized fats is essential for ensuring feed quality and safety and for developing strategies to minimize oxidation-related issues.

In swine feeding, the use of oxidized fats presents both opportunities and challenges for pig producers:

They offer a cost-effective energy source and contribute to waste reduction.

However, their inclusion in pig diets requires careful consideration due to their effects on nutritional quality, palatability, digestibility, and health risks.

Se deben equilibrar los beneficios y riesgos asociados con el uso de grasas oxidadas e implementar medidas de control de calidad adecuadas.

The benefits and risks associated with oxidized fats must be balanced, and appropriate quality control measures should be implemented.

It is essential to establish limits on the inclusion of oxidized fats in pig feed to ensure product safety and quality. Pig producers should comply with these regulations and monitor fat quality to mitigate potential health risks to pigs.