Changes in the Microflora and Physiology of the Anterior Intestinal Tract of Pigs Weaned at 2 Days, with Special Reference to the Pathogenesis of Diarrhea

Abstract

The gastrointestinal microflora and gastric physiology of piglets weaned at 2 days was compared with that of piglets allowed to continue sucking the sow. Although there was a significantly higher count of Escherichia coli in the stomach, duodenum, and jejunum of the early-weaned compared with sow-reared pigs, these differences were not detectable in samples from the ileum. There were no quantitative differences in lactobacilli and in streptococci between the two treatments. Lactobacillus fermentum, L. acidophilus, Streptococcus salivarius, S. bovis , and related biotypes were isolated from both groups of pigs. L. fermentum and S. salivarius were isolated more frequently from sow-reared piglets. The weight of digesta in the stomach was greater in weaned than in sucking pigs and was even greater in scouring weaned pigs, suggesting that in scouring pigs there may be gastric stasis. The gastric pH was higher in the weaned pigs at 4 days of age, but gradually decreased up to 10 days, during which time the lactic acid concentration rose. In weaned pigs there was a highly significant negative correlation between pH and lactic acid concentration in the stomach digesta, and also a positive correlation between pH and number of E. coli. These correlations suggest that lactic acid, from bacterial fermentation, is the major component in the regulation of gastric pH in weaned pigs. Three of twenty sucking pigs, but none of the weaned pigs, were secreting HCl (chloride concentration > 3 mg/g, pH < 3.5). In sucking pigs there was an inverse relationship between the chloride and lactic acid concentrations in the digesta. In weaned scouring pigs there was a nonsignificant increase in pepsin concentration in the stomach tissue. There was a threefold increase in the total proteolytic activity of the stomach tissue.

Gastrointestinal health and function in weaned pigs: a review of feeding strategies to control post‐weaning diarrhoea without using in‐feed antimicrobial compounds

“…Given the high gastric pH that is usually observed post-weaning, gastric stasis may contribute to development of PWD in piglets by allowing proliferation of pathogenic bacteria. Indeed, gastric stasis has been documented in early-weaned pigs as a contributing factor for PWD (White et al, 1969;Barrow et al, 1977). In addition, it has been reported that a stress gene, corticotrophin-releasing factor receptor 2, whose activation has been implicated in the inhibition of gastric motility (Martinez et al, 2004), is up-regulated in the jejunum of weaned pigs (Moeser et al, 2007).…”

Adhesion of Lactobacillus plantarum 423 and Lactobacillus salivarius 241 to the intestinal tract of piglets, as recorded with fluorescent in situ hybridization (FISH), and production of plantaricin 423 by cells colonized to the ileum

“…In pigs and most monogastric animals, the stomach and small intestine are dominated by Lactobacillus and Streptococcus spp., with generally higher cell numbers (10 7 -10 9 CFU ml )1 ) in the small intestine (Fuller et al 1978;Conway 1989). The main role of these organisms is to produce lactic acid to maintain a low stomach pH (Cranwell et al 1976;Barrow et al 1977). The most prevalent species in the porcine digestive tract are Lactobacillus acidophilus, Lactobacillus delbrückii, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus salivarius, Enterococcus bovis, Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Streptococcus intestinalis, Strep-tococcus porcinus, Streptococcus salivarius, Bifidobacterium adolescentis and Bifidobacterium suis (Raibaud et al 1961;Zani et al 1974;Barrow et al 1977;Fuller et al 1978;Collins et al 1984;Robinson et al 1984Robinson et al ,1988.…”

“…The main role of these organisms is to produce lactic acid to maintain a low stomach pH (Cranwell et al 1976;Barrow et al 1977). The most prevalent species in the porcine digestive tract are Lactobacillus acidophilus, Lactobacillus delbrückii, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus salivarius, Enterococcus bovis, Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Streptococcus intestinalis, Strep-tococcus porcinus, Streptococcus salivarius, Bifidobacterium adolescentis and Bifidobacterium suis (Raibaud et al 1961;Zani et al 1974;Barrow et al 1977;Fuller et al 1978;Collins et al 1984;Robinson et al 1984Robinson et al ,1988. Migration of pH and bile resistant strains to the larger intestine ensures a healthy balance between probiotic strains and opportunistic pathogens (Fuller et al 1978;Dunne 2001;Ohashi et al 2004).…”

Lactobacillus succession in the piglet digestive tract demonstrated by plasmid profiling

“…Lactobacilli are numerous in the digestive tract of pigs, constituting one of the principal bacterial groups inhabiting proximal regions of the tract (1). Some of these lactobacilli have the ability to colonize the epithelial surface lining the porcine esophagus and part of the stomach (the pars oesophagea), forming relatively thick bacterial layers (5,13).…”