Preparation Of Deep Enzymatic Hydrolysis Yeast Cell Wall And Its Effect On Growth And Development Of White Feathered Broilers

Yeast cell wall(YCW)is a green feed additive with immune enhancement function,whose bioactive substances mainly include β-glucan,mannan,proteins and lipids.At present,most YCW products on the market come from the waste products after the preparation of extracts in the field of yeast seasoning or the byproducts after the autolysis of brewer’s yeast mud and alcoholic yeast waste.The quality of these products is uneven,which affects their application in the field of animal breeding.In order to find the best quality YCW products and explore their effects on the growth and development of broilers,this topic uses yeast cell wall products from different raw materials to compare.Pure culture saccharomyces cerevisiae is used as raw material,with no obvious odor and less impurities.Pure culture yeast cell wall milk is used as raw material,and the product is obtained after deep enzymatic hydrolysis.The application test was carried out on white-feathered broiler and the indexes were measured.The research contents and results are as follows:1.The yeast cell wall product indexes from different raw materials were compared,and it was found that pure culture yeast cell wall dissolution rate was high without impurities,the particles were fine and uniform,and there was no obvious odor,which was more conducive to the later extraction of yeast cell wall and the basic preparation for further process optimization.2.By adding different combinations of enzymes to compare the solubility of yeast cell wall products,yeast cell wall polysaccharide content and so on to find out the appropriate production process.The yeast cell wall prepared by deep enzymatic hydrolysis of mannanase,glucanase,alkaline protease and cellulase showed more holes and fragments in the yeast cell wall and more fully exposed functional structure sites.The higher dissolution rate and the higher contents of functional substances β-glucan and mannan indicated that the insoluble glucan,protein,mannan and other macromolecules in yeast cell wall were transformed into soluble small molecular structures,and the cell wall enzymatic hydrolysis effect was more thorough,which was more conducive to the absorption of animal body.3.A total of 200 1-day-old white feathered broilers were randomly divided into 4treatment groups with 5 replicates per group and 10 broilers per replicate.There was no significant difference in average body weight among all groups(P > 0.05).The experimental groups were shown in Table 6.Control group(A)was fed a basal diet,test group B was fed a basal diet supplemented with 250 g/t yeast cell wall polysaccharide,test group C was fed a basal diet supplemented with 500 g/t yeast cell wall polysaccharide,and test group D was fed a basal diet supplemented with 1000 g/t yeast cell wall polysaccharide.The experiment lasted for 6 weeks.The effects of yeast cell wall on performance,immune function and intestinal development of broilers were investigated.The above results showed that the yeast cell wall of pure culture had high dissolution rate and no impurities,the particles were fine and uniform,and there was no obvious odor,which was more conducive to the late extraction of yeast cell wall.The contents of β-glucan,mannan and dissolution rate of yeast cell wall by deep enzymatic hydrolysis were higher than those by common enzymatic hydrolysis.Dietary yeast cell wall can significantly improve the production performance and immune function of column weight,improve the intestinal microecological environment,inhibit Escherichia coli and salmonella,significantly increase the immune organ index,Newcastle disease antibody level,and significantly reduce the serum levels of IL-1β and IL-6 inflammatory factors.Yeast cell wall has certain effect on intestinal morphological structure development of white feathered broilers in early growth stage,but has limited effect on intestinal improvement in later growth stage.Dietary 250 g/t and 500 g/t yeast cell wall can reduce intestinal p H value,and 250 g/t group has the highest microbial content in cecum.With the increase of supplemental dose,intestinal p H gradually increased and microbial quantity gradually decreased.The purpose of this study is to provide guidance for the deep development of yeast cell wall and its application in broiler breeding,and to provide new ideas for green and healthy broiler breeding.