Post-weaning diarrhoea (PWD) is a common condition in intensive swine production and is caused by enterotoxigenic Escherichia coli (ETEC) infection. With the aim of developing a sustainable product for protection against PWD, natural antibodies (immunoglobulins) derived from swine plasma were investigated as an alternative to antibiotics and zinc. Swine IgG isolated from slaughterhouse swine plasma-waste by expanded bed chromatography were shown to be reactive against ETEC in vitro1. Before launching large field studies on provision of enteral purified porcine IgG (ppIgG) for preventing PWD, we investigated safety aspects of ppIgG as well as its effect on ETEC colonization, and ETEC induced disease in a small scale challenge models of PWD.
Pathogens such a viruses and bacteria were efficiently removed by post IgG isolation procedures such as gamma irradiation (bacteria), and during the isolation process by a caprylic acid wash (virus) observed by spike-in experiments. In addition, weaner piglets receiving 4 grams per day of dietary ppIgG for 14 days after weaning showed no intestinal pathology or other disease signs compared to an age matched control group receiving no ppIgG. Furthermore, during experimental challenge of pigs with ETEC, ppIgG was shown to reduce shedding of the E. coli challenge strain and to improve the microbiota composition compared to a non-treated, challenged group1. Finally, ppIgG was tested for protection against disease in an ETEC challenge model with piglets post weaning, and results on the effect of ppIgG on clinical signs of diarrhoea in this model will be presented.
In conclusion, antibodies obtained from pig slaughterhouse plasma seem to have potential for the control of PWD.