Nutrient digestibility parameters as a tool for analysis of the intestinal health of broiler chickens

The study was performed with the objective of verifying raw soy feed, oxidized oil feed, and a control group. Performance evaluation was done at 7, 14, and 21 days of age. Metabolism assay was carried out between the 17th and 20th days for nutrient digestibility analysis. On the 21st day, two birds per repetition were sent for necropsy and collection of intestine fragments (duodenum and jejunum) for histomorphometric analysis. Eight to 14 days after treatment with Salmonella, individuals showed lower feed intake and feed conversion than the control group. Treatment with coccidiosis decreased all performance parameters in the control. Raw soybeans and oxidized oil induce lower weight gain and higher feed conversion compared to the control feed. Unlike after 14 days, at 21 days treatment with salmonella a decrease in weight gain was noted. For the group challenged by coccidiosis feed intake, the feed conversion remained lower than the control group. Undesirable effects on performance in the groups fed raw soybean and oxidized oil remained at up to 21 days. In the evaluation of digestibility, it was observed that raw soy had lower values for digestibility of dry matter, ether extract, and nitrogen balance due to intake. In addition, a lower ratio of villus:crypt measurements was observed. Lower villus height was found in the duodenum of the group challenged by coccidiosis. This group presented a positive correlation between the digestibility of ether extract and the duodenum, indicating that increased villus height implies an increased digestibility of ether extract. The results obtained for the jejunum showed a positive correlation with villus height in groups challenged by coccidiosis, raw soybeans, and oxidized oil; and to crypt depth in the group challenged with oxidized oil. The information obtained in the present study demonstrates that nutrient digestibility parameters can be useful tools for the analysis of the intestinal health of broiler chickens.