Histological and Microscopic Changes in the Digestive System of Broiler Chickens in Response to Probiotic Supplementation

Background: The supplementation of probiotics in poultry feed has gained significant attention for its potential to improve gut health, enhance digestion, and boost overall growth performance. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit to the host. Despite their widespread use, the precise effects of probiotic supplementation on the histological and microscopic structure of the digestive system in broiler chickens remain insufficiently explored. This study aims to investigate the histological and microscopic changes in the digestive tract of industrial broilers in response to probiotic supplementation. Materials and Methods: A total of ۱۰۰ one-day-old male broiler chickens (Ross ۳۰۸) were randomly divided into two groups: the control group, which received a standard basal diet, and the experimental group, which received the same basal diet supplemented with a probiotic mixture (Lactobacillus acidophilus, Bifidobacterium bifidum, and Saccharomyces cerevisiae). The study lasted ۴۲ days, and at the end of the trial, digestive tract tissues (including the crop, small intestine, and ceca) were harvested for histological analysis. Tissue samples were fixed in formalin, embedded in paraffin, and sectioned at ۵ μm thickness. Hematoxylin and Eosin (H&E) staining was used to evaluate general histopathological features, while periodic acid-Schiff (PAS) staining was employed to examine mucus production. The microscopic changes were further analyzed using electron microscopy to assess the ultrastructure of the intestinal lining. Results: Probiotic supplementation induced several histological and microscopic changes in the digestive system of broilers. In the small intestine, the experimental group showed a significant increase in villus height and crypt depth, indicating improved intestinal morphology and enhanced nutrient absorption capacity. Additionally, the villus surface area was larger, and the enterocyte density was higher, suggesting enhanced epithelial cell turnover. In the ceca, the probiotic-supplemented group exhibited increased mucosal thickness and a higher number of goblet cells, which are indicative of improved gut protection and immune function. Electron microscopy revealed better-preserved microvilli and a more intact intestinal epithelial structure in the experimental group. No significant changes were observed in the crop, though minor alterations in epithelial cell integrity were noted. Conclusion: Probiotic supplementation positively influenced the histological and microscopic characteristics of the digestive system in broiler chickens. Notable improvements in the morphology of the small intestine and ceca, including enhanced villus height, crypt depth, and mucus production, were observed, which could potentially improve digestive efficiency and gut health. These findings suggest that probiotics may serve as a beneficial feed additive in poultry farming, improving gut structure and function, and ultimately contributing to better overall performance in broiler chickens.

کلیدواژه ها:

Probiotics ، digestive system ، histology ، broilers ، intestinal health