Safer pig feeds without antibiotics

The use of antibiotics in animal feeds may soon be banned in the European Union. Despite positive effects on pig health and growth, there are growing concerns about bacterial resistance to antibiotics. This includes the risk of cross-resistance, with bacteria developing resistance to antibiotics used in human medicine.

In response to these concerns EUREKA project ANTIBIOTICS IN FEED has developed safe and healthy piglet feeds which are free from antibiotics. Crucially the new feeds can be quickly and easily introduced into today’’s feed manufacturing practice.

“When leaving out antibiotics there is a proven risk of diminished health, such as more diarrhoea and losses of piglets so it was important to develop alternatives to antibiotics that can minimize these problems,” explains Dr Annemarie Dirkzwager of Dutch lead partner Institute of Animal Nutrition De Schothorst.

The partners worked both separately and together, testing a whole range of products with different mechanisms. They evaluated dietary additions and different feed compositions in order to better understand the processes taking place in the piglet’s gut after weaning.

In vitro testing was used to explain the workings of the piglet in vivo experiments at cell level, by testing the effects of different feed additives in a CaCo-2 system representing a human cancer colon cell line. This behaves like piglet enterocytes during their growth and development. The tests showed that some organic acids had a positive effect on growth and improved gut condition.

The major problem that the partners had to tackle in the in vivo experiments was to ensure that the piglet test results were comparable and consistent. “Each partner had different facilities to do experiments with piglets. Also, the handling of the piglets was different, for example the age they were weaned and whether the piglets were kept outdoors or indoors,” says Dirkzwager.

Dirkzwager found a EUREKA project to be “a good and safe way to start up cooperation with less known partners. Once you have worked together in a project you know the reliability of the partner and the kind of results he obtains. Then it is easier to start further projects.”

The project’s experiments developed methods to strengthen processes in the gut and overcome negative effects caused by the lack of antibiotics. These alternative additives and standards for maximum or minimum levels of raw materials and nutrients are being used by feed manufacturers, including the project partners, to create safe piglet feeds without antibiotics. They have also been adopted by farmers.