PLASMA-LEVEL OF ANTISECRETORY FACTOR (ASF) AND ITS RELATION TO POST-WEANING DIARRHEA IN PIGLETS

Antisecretory factor (ASF) is a regulatory peptide which counteracts d iarrhoea in the pig; ASF is rapidly absorbed from the pig intestine, a nd significantly reduces the incidence of neonatal diarrhoea in the su ckling offspring. ASF is synthesized in the central nervous system, an d released to the blood stream via the pituitary gland. In two differe nt experiments (n = 8 and n = 4), the blood concentration of ASF was f ollowed in 5-weeks old piglets from day 7 before weaning up to day 12 days after weaning. In both experiments ASF concentrations were signif icantly (p < 0.01) lower on day three post-weaning, than either before weaning or on days 7 and 12 post-weaning. In another experiment, wher e plasma ASF activity was determined in relation to clinical signs of diarrhoea seven days post-weaning, it was found to be 0.87 +/- 0.08 un its/ml (mean +/- SEM) in healthy weaners (n = 15), but only 0.22 +/- 0 .05 units/ml in piglets suffering from diarrhoea (n = 15), the differe nce being significant. The faecal flora both of healthy weaners and of their matched controls suffering from diarrhoea were subjected to bac teriological examination before and after weaning, and found to be sim ilar in both groups, namely a mixture of aerobic and anaerobic Gram ne gative rods, Campylobacter jejuni, Staphylococcus aureus/epidermidis, and Enterococcus faecalis. No particular pathogen was predominant in a ny of the diseased animals.