3 reasons why you should be using butyrate in pig and poultry diets

Butyrate is a molecule with high potential for humans and animals. In this first article of three, we explain what butyrate is and give three solid reasons why it is a crucial element in pig and poultry diets.

Butyric acid is a short-chain fatty acid that is naturally produced in the hindgut of monogastrics and the rumen of ruminants. It has the potential to trigger several beneficial effects in the digestive tract of humans and animals.

In humans, butyrate has been studied as a tool in the prevention and treatment of inflammatory bowel diseases and colon cancer. In animal production, butyrate is added to the feed to improve the digestive tract development and maintenance, which is crucial to prevent disturbances linked to the challenges faced by the animals. This purpose of prevention makes it a perfect fit in today’s approach to animal production and diet formulation.

Butyric acid itself is a volatile and corrosive liquid, with a very pungent smell and is therefore very rarely applied in animal feed in this form. This is one of the reasons why derivatives of butyric acids are used, most commonly salts (coated butyrates) and glycerides (butyrins). Innovations made over the years in coated butyrate products have increased precision delivery of the molecule, enhanced product stability and reduced odor associated with the product.

Here are 3 reasons why the momentum is right to start using butyrate:

1. Butyrate improves gut health

A healthy gastrointestinal system (gut) is important for animals to achieve their maximum production potential, to increase feed efficiency and prevent intestinal infections and disease. And this is especially important for young animals, where the digestive tract is immature and not all feed ingredients can be digested well.

Butyrate promotes gut health in different ways, such as:

• Butyrate stimulates cell renewal and differentiation of the cells of the intestinal wall (the enterocytes). This will increase gut barrier function and gut integrity and promote mucosal healing; all needed for an efficient absorption of nutrients from the diet and to prevent gut wall infections.
• Butyrate modulates the thickness of the mucus layer of the intestinal wall. A healthy mucus layer forms a protective barrier between the underlying epithelium and the lumen containing toxins and bacteria amongst others.
• Butyrate is a regulator and a key signaling molecule of the intestinal microbiome. It improves beneficial bacterial populations (such as Lactobacilli and Bifidobacteria) and reduces the colonization of harmful bacteria (such as Salmonella, Campylobacter and E. coli) in the digestive tract of animals. More beneficial bacteria means less chance for the pathogenic ones to proliferate and cause infections or disease.
• Butyrate increases the villus height to crypt depth ratio. This increased ratio leads to increased absorptive capacity of the intestinal wall, which will benefit nutrient digestibility and optimized nutrient utilization (for e.g. proteins). In addition, butyrate stimulates the release of digestive enzymes, needed for optimum nutrient digestibility and feed efficiency.

2. Butyrate helps the immune system

A strong immune system in farm animals is important to prevent diseases (and antibiotic use), animal welfare and to reach the animal’s full genetic potential. The gut is an organ that has the most immune cells in the body (approximately 70%) and is part of the first line of active defense against pathogens.

Butyrate promotes the immune system in different ways, such as:

• Butyrate reduces a range of pro-inflammatory cytokines (through the inhibition of the so-called nuclear factor kappa B (NF-κB) pathway). Reducing these types of cytokines helps to reduce the damage caused by oxidative stress and inflammation.
• Butyrate increases anti-inflammatory cytokines (such as interleukin-10). Butyrate also modulates lymphocyte proliferation and macrophage activity and activation and stimulates the secretion of antibodies. These positive effects of butyrate will prevent oxidative stress and inflammation and create a faster and stronger immune response.
• Butyrate is an inducer of the enzyme intestinal alkaline phosphatase (IAP). This enzyme is a potent anti-inflammatory enzyme that removes a phosphate group from toxic products such lipopolysaccharide (LPS) or endotoxins that are present in the gut. This will stop inflammation cascade and the release of inflammatory cytokines.

3. Butyrate suppresses intestinal Salmonella and Campylobacter growth

Worldwide there is increased consumer and governmental focus on food safety. The European Union for example has set clear targets to combat Salmonella. Strict regulations have been implemented, which have brought added costs to control and monitoring programs for animal production.

Livestock producers are trying to control Salmonella load on-farm in order to reduce (cross-) contamination in slaughterhouses, thereby decreasing the risk to humans. Besides biosecurity measures and vaccination programs, producers are using feed additives as part of a holistic control program.

Butyrate helps to control Salmonella in different ways, such as:

• Butyrate can down regulate Salmonella virulence, both by direct effects on virulence gene expression and by modulating activity of host cells. Studies have shown that precision-delivery coated butyrate is able to decrease Salmonella or Campylobacter colonization in broilers and swine.
• Butyrate triggers the expression and secretion of antimicrobial host defense peptides in the digestive tract of animals, thereby limiting the growth of several enteric bacterial genera, including Salmonella.

Conclusion

The focus on and research around gut health in farm animals has accelerated in the last few years, due to stricter regulation on antibiotic use and the ban on therapeutic levels of zinc oxide in swine diets amongst others. Butyrate has the capacity to positively trigger different mechanisms in the gut of monogastrics. A healthy gut – in turn – is a prerequisite to improvements in growth, performance, feed efficiency and animal health.

Learn more about butyric acid and
butyrate in the technical booklet

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