Ban on antibiotics in animal feed led to the AF protein.
In 1986 the use of antibiotics in animal feed was banned in Sweden, as one of the first countries in the world. The ban was due to an escalating antibiotic resistance developing in animals, similar to that seen in human antibiotic use. Antibiotics in animal feed are used to prevent for instance post-weaning diarrhoea in piglets. The ban resulted in an increased prevalence of diarrhoea. The suffering this caused and the increased number of deaths due to stress and infectious disease epidemics was disastrous and caused noticeable profit loss.
To come to terms with the problem and possibly find an alternative feed, a joint scientific project was initiated, combining the expertise from veterinary medicine, microbiology, infectious disease and immunology.
In order to find a new feed that could be used in treating the post-weaning diarrhea in piglets, attempts were made based on experiments on cholera toxin in rats and the discovery of the AF protein by Professors Lange and Lönnroth. Initially the stimulation of the piglets own AF was made by using feed with additives of sugar and amino acids in defined proportions.
Urine samples showed that there was a correlation between the AF-level and diarrhea. Samples from pigs without diarrhoea had a high level of AF whereas samples from pigs with diarrhoea had low levels of AF. The use of this specialised feed gave immediate effect, resulting in substantially lowered prevalence of diarrhoea and significantly fewer deaths in piglets.
From this point research began to develop a feed that in itself contained the proper amounts of amino acids and sugars, without the need for additives. A production process was created and in 1991 a feed intended for piglets and sows was introduced under the brand name of Trygge® . A large number of Swedish pigs are now weaned with a feed that induces AF, thus reducing the effects of both invisible (subclinical) and visible (clinical) diarrhoea.