Plasma Level of Antisecretory Factor (ASF) and its Relation to Post‐Weaning Diarrhoea in Piglets

Abstract

Summary Antisecretory factor (ASF) is a regulatory peptide which counteracts diarrhoea in the pig; ASF is rapidly absorbed from the pig intestine, and significantly reduces the incidence of neonatal diarrhoea in the suckling offspring. ASF is synthesized in the central nervous system, and released to the blood stream via the pituitary gland. In two different experiments (n = 8 and n = 4), the blood concentration of ASF was followed in 5‐weeks old piglets from day 7 before weaning up to day 12 days after weaning. In both experiments ASF concentrations were significantly (p < 0.01) lower on day three post‐weaning, than either before weaning or on days 7 and 12 post‐weaning. In another experiment, where 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 units/ml (mean ± SEM) in healthy weaners (n = 15), but only 0.22 ± 0.05 units/ml in piglets suffering from diarrhoea (n = 15), the difference being significant. The faecal flora both of healthy weaners and of their matched controls suffering from diarrhoea were subjected to bacteriological examination before and after weaning, and found to be similar in both groups, namely a mixture of aerobic and anaerobic Gram negative rods, Campylobacter jejuni, Staphylococcus aureus / epidermidis, and Enterococcus faecalis. No particular pathogen was predominant in any of the diseased animals.

Antisecretory factor as a potential health-promoting molecule in man and animals

“…AF is transferred from the sow to the fetus across the placenta (45) . In piglets, AF activity in plasma has a cyclic variation; it declines at weaning, reaching the lowest level on the third day post-weaning (46) . The onset of diarrhoeal disease is significantly correlated with the low plasma AF activity (5) .…”

Distribution and immunoregulatory properties of antisecretory factor

“…Previous literature suggests that serum ASF is regulated by food intake. [26][27][28] However, we found no difference in serum ASF levels between animals that have been food-deprived overnight versus 2 h postprandial animals (data not shown). Thus, the reason for this variability of serum ASF levels remains unresolved.…”

“…Indeed, soluble ASF has been demonstrated in plasma, 28 and has antisecretory activity in the rat intestinal loop experimental model. TLD-1A8A did not stain T cells, indicating that the in vitro effect of enhancing T-cell proliferation was not due to a direct binding of the mAb to the T cell itself.…”

Effects of age and zinc supplementation on transport properties in the jejunum of piglets

“…As a possible explanation for the decrease in secretory capacity after weaning, Lange et al. () have demonstrated that the antisecretory factor (ASF) increases from negligible levels in piglets younger than 5 week of age to high levels in older pigs. Sensitivity to secretagogues is thus assumed to decrease with age (Grondahl et al., ; Erlwanger et al., ) and with the maturation of the intestinal tissue (Cummins et al., ).…”