The interactive effect of phytase and coccidia on the gross lesions as well as the absorption capacity of intestine in broilers fed with diets low in calcium and available phosphorous.

In an experiment with 2x2 factorial design, the influence of dietary phytase on the intestinal lesions as well as the absorption capacity of intestine for D-xylose in broiler chickens provided with a diet low in calcium (Ca) and available phosphorus (aP) and challenged with Eimeria oocysts, was evaluated. Four groups of 20 1-day-old male broiler were provided with diets low in total Ca and aP (8 and 3g/kg instead of 10 and 5g/kg of Ca and aP in the diet, respectively). On day 10, 10 chicks from each group were randomly kept in individual raised floor wire cages to adopt environmental conditions. The experimental groups were as follows, Group 1: received no Eimeria oocysts (negative control), Group 2: received oocysts of mixed Eimeria species on day 15 to create an experimental coccidiosis (positive control), Group 3: negative control received phytase enzyme in their diet, from the first day of life, and Group 4: positive control received phytase enzyme in the diet. On day 20, after 12h fasting, the D-xylose absorption test was performed and immediately after that, the intestinal lesion scoring was carried out. The results showed that coccidiosis in Groups 2 and 4 produced progressive lesions in intestinal tract and reduced the concentration of plasma D-xylose in Group 2 when compared to Groups 1 and 3. Dietary phytase had no influence on the concentration of plasma D-xylose in un-infected birds. The enzyme had no influence on the intestinal lesions caused by coccidiosis as well. However, it increased the plasma D-xylose concentration of Group 4 to the level that it was comparable with Groups 1 and 3, at 45 and 90min post-ingestion of the solution. It was concluded that the addition of phytase enzyme to the low Ca and aP diet, increased indirectly the absorption capacity of intestine for D-xylose in infected chickens most probably through the improvement of mechanisms involved in the absorption and transport of D-xylose.