The effect of ovalbumin and mannose-conjugated ovalbumin on the prevention of Salmonella adherence to the intestinal epithelium of chickens

This investigation was designed to determine the effect of intact ovalbumin and mannose-conjugated ovalbumin on the prevention of Salmonella typhimurium adherence to the epithelium of small intestine of chickens. Mannose-conjugated ovalbumin was produced by Maillard-type reaction between chicken ovalbumin and D-mannose at 60°C. The results revealed that incubation up to 96 hrs caused the highest amount of covalent attachment of mannose to the ovalbumin. In order to determine the effect of native ovalbumin and mannose-conjugated ovalbumin on the prevention of S. typhimurium adherence to chicken small intestine, 60 one-day-old chicks were randomly assigned to 3 groups, with two replicates and ten birds per pen. Groups 1, 2 and 3 received normal diet, diet containing 0.5% native ovalbumin and diet containing 0.5% mannose-conjugated ovalbumin, respectively, for 12 days. On day 3, all groups received 1.3 × 106 CFU of S. typhimurium orally. On days 4, 7 and 10, two chicks from each group were killed and mean log 10 of CFU (colony forming unit) of Salmonella per 1 g tissues of cecum, liver and spleen was determined. Four chickens from each group were killed on day 12 and were examined as described above. The results showed that in group 3, number of viable Salmonella in cecum, liver and spleen was lower than groups 1 and 2. However, the difference was significant only in cecum on days 4 and 7 (P<0.05). These preliminary results suggest that mannose-conjugated ovalbumin might be effective in prevention of Salmonella colonization in the epithelium of small intestine if incorporated in the diet of chicks.