Demedication: what are the alternatives to antibiotics in pig production?

Since the 2011 Action Plan on antibiotic resistance, reducing antibiotic use has become a major concern for European pig farms. Yet, recent studies have shown that there are in fact a whole range of substances that, when used in combination with feed and other factors, could provide interesting long-term alternatives to antibiotics. These strategies are based on a holistic approach to all aspects of the farming system.

What is ‘antibiotic resistance’ in pig production?

Usually, micro-organisms are considered as pathogens which have to be fought against in order to be destroyed: the systematic use of antibiotics in order to deal with diseases derives from this logic. Current bacteria have adjusted to this reality through genetic adaptation and they have gradually built resilience against these molecules: known as ‘antibiotic resistance’.
Bacteria resilience has become a major social issue. A huge part of these molecules are similar whether they are used for human or animal medication.

A European Action Plan aims to reduce the use of antibiotics in order to limit overall antibiotic resistance. To trigger a post-antibiotic era, this plan also intends to foster social change in the way we use antibiotics: that is no longer curatively but preventively.

To minimise the use of antibiotics, many studies have been carried out to try to better understand and characterize the relationships between micro-organisms and microbiota. In fact, living species are an ecosystem composed of microbes. This system needs to be well-balanced and treated in order to maintain a good host health. To achieve this aim, the microbiota is designed to fulfill the useful and essential specific functions enabling the host to survive.

Using additives as alternatives to antibiotics in piglet feed

There are several alternative solutions to antibiotics: that is to say a wide and varied range of solutions with different mechanisms and of various chemical nature are available such as organic acids, probiotics, prebiotics, essential oils, herbs and spices….

Probiotics are live micro-organisms: they act in a specific way on the digestive system and immune system and maintain a constant interaction with microbiota.

Prebiotics are nutrients used by microorganisms in the intestine, allowing the beneficial bacteria population to develop and multiply.

This phenomenon also helps to prevent pathogenic bacteria from developing in the intestine. This action may be enforced by the use of organic acids, medium chain fatty acids and essential oils.

Vegetal extracts, essential oils, antioxidants or beta glucans are also known to have a positive impact on the immune and oxidative status of the animals. The main challenge to make them easier to use and to be less dependent on in-feed antibiotics lies in understanding their patterns of action and assessing their efficiency.

How do environmental and nutritional factors influence piglet microbiota?

Intestinal microbiota can be modulated and influenced by genetic, environmental and nutritional factors, other than additives. It is important to control the use of additives in order to combine their action with an adapted nutritional strategy.

This feeding strategy, which is based on protein level, energy input and amino acid ratios, has a major impact on microbiota and also on digestive security. When it is well balanced, the piglet’s intestinal microbiota highly contributes to improve its growth performance.

The main nutrients reaching the hindgut are fibres and the indigestible fraction of protein. Piglet microbiota is directly involved in fibre digestion: the fermentation of fibres by the microbiota produces volatile fatty acids (butyric acid, propionic acid, acetic acid). These acids foster the growth of epithelial cells and the area of absorption, which, in turn, improves the nutrients digestion in the intestinal tract. In addition, the production of volatile fatty acids decreases the intestinal environment pH, which limits the development of pathogenic bacteria.

Therefore the fermentation of fibres has a positive action on the intestinal metabolism of piglets. At the same time, the fermentation of indigestible protein by microbiota releases toxics compounds (biogenic amines, ammoniac), this, in turn alters the intestinal mucosal membrane. It eventually leads to malabsorption and increases fluids, causing diarrhœa in piglets.

Formulating a secured feed requires increasing protein quality and decreasing protein quantity as well as controlling fibre nature (solubility, fermentability, viscosity, water holding capacity). When combined with additives, the feeding strategy contributes to well-balanced microbiota.

Many other factors can come into play to positively influence piglet microbiota such as the special link between the sow and piglet microbiota and bacterial diversity. For more information, please contact us.