All forms of butyric acid improve the health of turkeys in intensive production

This conclusion was reached by Polish scientists after testing the use of butyric acid in various forms. 

The benefits of butyric acid supplementation in turkey rearing were discussed by scientists from the Department of Animal Nutrition and Feed Science, University of Warmia and Mazury in Olsztyn, in an article published in the journal Animals 2022, on the MDPI portal.

Authors Zbigniew Makowski, Krzysztof Lipinski and Magdalena Mazur-Kusznierek noted the following factors.

“Antibiotic growth promoters have been used for decades to improve the performance of farm animals kept in adverse environmental conditions in intensive production. They were administered to animals to regulate the intestinal microbiota by inhibiting the growth of pathogenic microorganisms and the production of toxins.

However, this practice eventually contributed to the formation of antimicrobial resistance in bacteria such as Salmonella, Campylobacter, Enterococcus and strains of Escherichia coli, with animal and human health risks.

On January 1, 2006, the European Commission banned the use of antibiotics as growth promoters in animal nutrition in the European Union. One solution was to introduce alternative growth promoters to keep animals healthy and increase productivity.

Probiotics, prebiotics, enzymes, phytobiotics and organic acids have gained particular popularity in European animal husbandry.

Organic acids such as acetic, butyric, propionic, fumaric and lactic acids have beneficial effects on gut health and bird growth performance.

They can be included in the diet as sodium, potassium and calcium salts, in free form, as protected/coated salts and as glycerides.

Due to their antimicrobial properties, organic acids act on the gastrointestinal tract of birds, lowering the pH of intestinal digestion, reducing the abundance of pathogenic bacteria, promoting the growth of Lactobacillus, improving nutrient absorption and enhancing the proliferation of intestinal epithelial cells.

Butyric acid has strong antimicrobial activity, serves as an energy source for epithelial cells in the colon and terminal small intestine, thereby improving nutrient absorption.

Butyric acid is usually used in the form of butyrate (calcium or sodium salt) because it is odorless.

The principle of action is that when sodium butyrate reaches the bird's stomach, it releases the Na ion. Due to the low pH, another fraction, butyrate, is rapidly converted to the undissociated form, defined as butyric acid.

This form has antimicrobial properties and can lower stomach pH by increasing the conversion of pepsinogen to pepsin, which increases the rate of nutrient absorption.

Butyric acid also stimulates the development of gut-associated lymphoid tissue and the functional development of the gastrointestinal tract in terms of digestion and absorption of nutrients. In addition, it reduces bacterial colonization of the intestinal wall and thereby reduces the predisposition to diarrhea.

There is debate whether butyrate is more effective when it is served in a protected form such as encapsulation or glyceride esterification.

Therefore, the aim of this study was to compare the effectiveness of butyric acid glycerides (BAG), sodium butyrate (SB), and coated sodium butyrate (CSB) in turkey feeding based on indicators of poultry growth, carcass yield, meat quality, faecal dry matter content, prevention of pillow dermatitis and cost-effectiveness.

In the present study, 400 turkeys of the 5th BIG-6 cross were involved, where the experimental diets were fed with various forms of butyric acid.

Poultry production efficiency and meat yield were improved when butyric acid glycerides or coated sodium butyrate were added to the diet.

In birds receiving experimental diets, an improvement in the condition of the paw pads and an increase in the dry matter content in feces was noted.

The addition of butyric acid in various forms to turkey diets has increased the economic efficiency of production.

For the prevention of diarrhea, coated sodium butyrate and butyric acid glycerides are of particular value.

Butyric acid has the ability to change from an undissociated form to a dissociated one (depending on the pH of the medium), which enhances its antimicrobial effect.

When the acid is in its undissociated form, it can diffuse through the bacterial semipermeable membrane into the cell cytoplasm.

Inside the cell, where the pH is maintained around 7, the acid dissociates and inhibits the nutrient transport systems and bacterial cell enzymes (eg, catalase or decarboxylase).

The effectiveness of an acid in inhibiting harmful microorganisms depends on its pKa value, which is the pH at which 50% of the acid dissociates.

Butyrate must be in an undissociated state before it reaches the lower small intestine in order to have a more potent antimicrobial effect. Protected forms of butyric acid can solve this problem, as they are available even in the proximal and distal intestines of birds.

With regard to the prevention of pylorus dermatitis, in the present study, all forms of butyric acid added to turkey diets resulted in an increase in fecal dry matter and a decrease in the incidence of pylorus dermatitis. An increase in dry matter in the faeces indicates a decrease in water excretion, which positively affects the quality of the litter and reduces the incidence of pillow dermatitis.