تاثیر سطوح مختلف دیواره سلولی مخمر بر عملکرد و جمعیت میکروبی سکوم بلدرچین ژاپنی

Introduction: Poultry nutrition accounts for about 60 to 70 percent of poultry farming costs. Therefore, efforts should be made to develop economic poultry production with the help of scientific principles of nutrition. Yeast and yeast derivatives are among the additives recommended for use in poultry diets to improve performance. Yeast cell walls constitute 25 percent of the dry weight of yeast cells and, in addition to their protective role, are also involved in metabolic processes. Yeast cell wall components include mannoproteins, beta-glucan, mannan oligosaccharide, chitin, and N-acetylglucosamine. Beta-glucan, with its helical structure, has the ability to absorb mycotoxins. Yeast cell walls play an important role in improving the health of livestock and poultry by absorbing toxins in their feed. The role of mannan oligosaccharide in preventing the colonization of pathogens in the digestive tract has been proven. With their prebiotic role, oligosaccharides stimulate the growth of beneficial anaerobic bacteria in the digestive tract and indirectly affect the population of pathogens and improve intestinal morphology.
Materials and Methods: An experiment was designed to investigate the effect of different levels of yeast cell wall on functional traits and blood parameters. In this experiment, four levels of yeast cell wall (0, 0.5, 1, and 1.5 g/kg) and 360 one-day-old Japanese quails were used. The experiment was conducted in a completely randomized design with 4 treatments and 6 replications. The experiment was conducted in a completely randomized design with 4 treatments and 6 replications. Performance traits including feed intake, weight gain, and feed conversion ratio were measured throughout the experiment. At the end of the experiment, intestinal sampling was performed to examine intestinal tissue, cecal contents were sampled to examine the cecal microbial population, blood sampling was performed to examine blood factors, and carcass weight was measured.
Results and discussion: The results of the experiment showed that the consumption of yeast cell wall increased feed intake and improved weight gain of birds at the age of 22 to 35 days and the entire rearing period (P<0.05). It also reduced feed conversion ratio at the age of 22 to 35 days (P<0.05). The population of lactobacilli in the cecum increased under the influence of yeast cell wall consumption and the population of Escherichia coli decreased (P<0.05). The population of coliforms was not affected by the experimental treatments (P>0.05). Carcass components (Percentage of digestive tract weight, weight of breast, thighs, forestomach, gizzard, liver), small intestine length (duodenum, jejunum and ileum) and the length of the cecum, blood parameters (Triglycerides, cholesterol, glucose, HDL and LDL) and serum liver enzymes (Alanine Aminotransferase, Alkaline Phosphatase, Aspartate Aminotransferase) were also not affected by the experimental treatments (P>0.05). Among the histological characteristics of the duodenum and jejunum, villus height and villus height to crypt depth ratio increased under the influence of yeast cell wall consumption (P<0.05). The beneficial effects of yeast cell walls are primarily associated with active immune function due to the presence of beta-glucan and mannan oligosaccharides in yeast products. The use of yeast products in poultry diets has been reported to improve immunity, balance of microbial populations, and development and health of the gastrointestinal tract. In addition, these additives can improve the digestion and absorption of nutrients in the feed. And through this, improve growth and ultimately improve the performance of the bird. Mannan oligosaccharide present in the yeast cell wall has a high ability to bind to pathogenic bacteria and thus exerts prebiotic properties. The balance between pathogenic and beneficial bacteria increases villi length and decreases crypt depth, which are biomarkers for improved intestinal morphology. Improved intestinal morphology can increase the activity of digestive enzymes and ultimately improve digestion. Longer villi indicate a more mature epithelium and increased absorptive function due to an increased absorptive area of the villi. The development of intestinal morphology can reflect the health status of the animal's digestive tract. Higher villi height increases the activity of enzymes secreted from the ends of the villi, resulting in better digestibility.
Conclusion: The results of this study showed that the use of levels of 1 and 1.5 g/kg of yeast cell wall improved the cecum microbial population and histological characteristics of the duodenum, although no effect was observed on the overall performance of the birds.