ABSTRACT
The aim of this study was to assess the addition of intestinal alkaline phosphatase (IAP) to diets on the count of bacterial populations, pH of digestive organ contents, histopathological description, proinflammatory markers, hepatic glycogen reserve, and diarrhoea incidence of piglets challenged with Escherichia coli. Sixty-four crossbred piglets (7.16±0.28 kg body weight, 25-days-old) were assigned to four treatments in a completely randomised block design: negative control (NC), NC + antibiotic (ANT), NC + 15 mg IAP, or NC + 30 mg IAP kg−1 of diet, eight replications of two piglets per experimental unit. All piglets were orally challenged with 6 mL of a solution containing enterotoxigenic Escherichia coli K88 at 106 CFU mL−1 at 15 days of experimentation. The study lasted for 19 days. At the end of the experimental period, the piglets were slaughtered (six animals per treatment). Enterobacteriaceae in caecum and colon was lower in piglets on 30 mg IAP than with ANT and NC, ANT or 15 mg IAP, respectively. Enterobacteriaceae adhered to the mesenteric lymph nodes (MLN) was greater in piglets fed ANT than the other treatments. Lactic acid bacteria (LAB) count in caecum was greater in piglets fed NC and ANT. In MLN, LAB count was greater in ANT and 30 mg IAP-fed piglets compared with 15 mg IAP. Piglets in 30 mg IAP in diet showed a tendency for lowering tissue necrosis compared with NC or ANT. Piglets fed 30 mg IAP showed a reduction in diarrhoea incidence in the pre- and post-challenge compared with 15 mg IAP and all other treatments, respectively. Based on the criteria, addition of 30 mg IAP to diet inhibits Enterobacteriaceae population and suggests a potential effect in mitigating intestinal injuries, as observed in piglets in the NC for some of the parameters investigated.
alkaline phosphatase; bacterial populations; diarrhoea incidence; intestinal histopathology; proinflammatory marker; weanling pigs