Document Type : Research Paper
Authors
1 Department of Animal Science, Animal Science and Food Technology Faculty, Agricultulal and Natural Resources University of Khuzestan, Mollasani, Iran
2 1. Department of Animal Science, Animal Science and Food Technology Faculty, Agricultural Science and Natural Resources University of Khuzestan, Mollasani, Iran
3 Department of Biology, Faculty of Science, and Biorefinery Research Center, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract
Objective: This research aims to investigate the effects of processing rice and wheat brans using different fermentation methods (by bacterium, fungus, ruminal fluid) on the performance, intestinal morphology, and cecal microbial population of Ross 308 broiler chickens. Bran (rice and wheat), as a byproduct is rich in nutrients and fiber, which can be used as an alternative food source in poultry nutrition in limited amounts. However, the presence of anti-nutritional compounds in bran such as fiber and phytic acid, limits its digestibility and absorption. It seems that fermentation processing can enable optimal use of bran by breaking down and increasing the absorption of these compounds.
Method:In this experiment, 400 one-day-old broiler chicks, commercial strain Ross 308 (mixed sexes) were studied in a completely randomized design with factorial arrangement (4 × 2) for 42 days. Experimental factors included different processing methods (no processing, fermentation with Bacillus Subtilis bacteria, fermentation with Aspergillus Niger fungus, and fermentation with rumen fluid) and bran type (wheat and rice at 10% of the diet), and their effects on performance (feed intake, weight gain, feed conversion ratio), intestinal morphology and caecal microbial population, and pH of different parts of the digestive tract (jejunum, duodenum, jejunum, and ileum) were evaluated.
Results: The interaction effect of bran type and processing method on feed intake and total weight gain was not significant, but it had a significant effect on feed conversion ratio. Specifically, the groups that received wheat bran and rice fermented with fungus had the lowest feed conversion ratio. In examining the main effect of processing method, fermentation of bran with fungus increased feed intake compared to raw bran and bran fermented with rumen fluid. Consumption of wheat bran, compared to rice bran, resulted in a significant improvement in weight gain and a decrease in feed conversion ratio. Duodenal villus height was significantly increased in the fermentation method with fungus compared to raw bran and fermentation method with bacteria, but there was no significant difference with the fermentation method with rumen fluid. The highest ratio of villus height to duodenal crypt depth was observed in the bran fermentation method with fungus. The results showed that wheat bran, compared to rice bran, increased villus height and epithelial thickness and decreased jejunal crypt depth. The ratio of villus height to jejunal crypt depth showed a significant increase in the two processing methods with fungus and rumen fluid. The ratio of villus height to crypt depth in the ileum showed the highest value in the group receiving rice bran fermented with fungus and rumen fluid as well as wheat bran fermented with fungus. The lowest ratio of villus height to crypt depth in the ileum was observed in the group receiving raw rice bran. The interaction effect of experimental factors on the population of lactobacilli in the cecum was significant. Birds fed wheat bran fermented with rumen fluid showed a higher population of lactobacilli in the cecum compared to other treatments except rice bran fermented with fungus. Birds fed fermented bran had lower levels of Escherichia coli and cecal coliforms than birds fed raw bran.
Conclusion: The results show that fermentation processing of wheat bran and rice bran, especially using the fungus Aspergillus Niger, can be used as an effective strategy in feeding broiler chickens due to improved performance, increased villus height and decreased intestinal crypt depth, increased population of beneficial lactobacilli, decreased population of harmful bacteria, and decreased intestinal pH.
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