Effects of Yersinia enterocolitica infection on growth of the body and internal organs in newborn colostrum-deprived piglets.

Yersinia enterocolitica enteritis in newborn, colostrum-deprived piglets fed a human milk formula caused a reduced milk intake and decreased gain in weight but not length of the body. In infected piglets, the weight of the liver was less than in controls but other abdominal organs were unaffected. The weight of the caecum and small intestinal muscle were greater, but the length and weight of the small intestine and colon were not different. In infected piglets, the RNA concentration of the small intestinal mucosa was elevated whereas the concentrations of DNA and protein were unchanged, and total lactase activity was reduced. After antibiotic therapy, the liver weight was greater and the body weight increased at the same rate as the controls but was still lower at 14 days. The body weight of the control piglets increased linearly over the 14 days after birth. The stomach, pancreas and spleen grew more rapidly, but the liver more slowly, than the body as a whole but the kidneys had a minimum relative weight at 5 days. The total lactase activity and protein and RNA concentrations of the small intestinal mucosa decreased with age, the RNA to a greater extent than the protein.