Dietary non-pharmacological alternatives to the use of antibiotics as growth promoters in swine

The first weeks after weaning are a critical stage for piglets characterized by high incidence of diarrhoea and low weight gain. These problems were counteracted with the use of antibiotic growth promoters that may as a side-effect induce the selection of antibiotic-resistant genes in animal and human pathogens. For this reason, the European Union decided to completely ban the antibiotics used as growth promoters as of January 2006. As a consequence of this decision, alternative strategies to modulate the piglet gastrointestinal environment have been the object of many studies. The use of non-pharmaceutical dietary supplements, such as organic acids, prebiotics, probiotics, and essential oils has been shown to improve piglet post-weaning health and growth performances but results are sometimes controversial. Moreover, the role of molecules that can influence gastrointestinal and immune development in the newly weaned piglet has been investigated. The proper choice and use of a non-pharmacological dietary supplement might improve piglet productivity but it has to be considered that dietary supplements usually increase the feed price, which means that the gains in productivity should exceed the increased costs.