What are Mannan Oligosaccharides?

Manno-oligosaccharides are widely found in konjac flour, guar gum, sesbania gum and various microbial cell walls (glucomannan oligosaccharides). At present, the commercially available manno-oligosaccharides are mainly produced by enzymatic hydrolysis. They are a glucomannan complex extracted from yeast cell walls rich in poultry metal oxide enzymes by fermentation. In animal production, they are used as feed additives to enhance the immunity of animals, reduce the incidence and mortality of gastrointestinal diseases, and increase daily weight gain and feed conversion rate. They have great development potential.

Manno-oligosaccharides have certain immunogenicity and can stimulate the body's immune response. In addition, they can bind to certain toxins, viruses and fungal cells, and as adjuvants for these exogenous antigens, they can slow down the absorption of antigens and increase the titer of antigens, thereby enhancing the cellular and humoral immune responses of animals. They can also stimulate the liver to secrete sugar-binding proteins and affect the immune system. This protein can bind to bacterial sandwiches and trigger a series of complements, thereby initiating a response from the immune system. Kim et al. (2000) reported that both manno-oligosaccharides and -glucans can accelerate the recovery of suppressed piglet immune systems and can effectively reduce mortality and diarrhea rates.

Reaction Principle

Manno-oligosaccharides were found to increase the level of IgA in broiler bile by 14.2% (Savvage et al., 1996a), and to increase the level of IgA in the intestinal mucosa of turkeys, and significantly increase the IgG content in the blood of turkeys (Savvage et al., 1996b). Spring (1998) found that manno-oligosaccharides could significantly increase the levels of IgA, IgG and IgM in the serum and intestinal mucosa of sterile piglets, as well as the level of interleukin-2 (IL-2) in the blood, enhance the function of T lymphocytes and the activity of primitive lymphocytes in the small intestine, enhance the phagocytosis of leukocytes in the small intestine, and promote the release of IFY-cytokines by activated lymphocytes, thereby promoting the movement of macrophages, body fluids and proteins to the site of infection. For ordinary piglets, manno-oligosaccharides only significantly increased the level of serum IgA, but had no significant effect on IgG and IgM.

Manno-oligosaccharides can significantly increase the PHA-lymphocyte transformation rate and phagocytic ability of phagocytes in suckling piglets (Spring et al., 1997, 1998; Okareka, 1998; Shao Liangping, 2000a); significantly increase the phagocytic ability of chicken leukocytes and PHA lymphocyte transformation rate, effectively improve the intestinal microbial environment of chickens, significantly reduce the number of Escherichia coli and the pH content of the cecum and ileum, and significantly increase the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in chicken serum (Shao Liangping, 2000b) .

Summary

Studies have shown that manno-oligosaccharides can control the microecological environment of the gastrointestinal tract of animals, promote the growth and reproduction of beneficial bacteria, inhibit the adhesion and colonization of harmful bacteria in the intestine, and maintain a normal gastrointestinal environment. First, it can selectively promote the proliferation of beneficial bacteria such as bifidobacteria and lactobacilli in the animal intestine, thereby forming a microecological competitive advantage in the gastrointestinal tract, and directly inhibit the growth and reproduction of exogenous bacteria and intestinal spoilage bacteria, thereby exerting the normal functions of normal intestinal flora in terms of barrier, nutrition and immunity.

Secondly, it can hinder the binding of lectins on the surface of bacteria and specific sugar molecules of intestinal mucosal epithelial cells, prevent the adhesion and colonization of pathogenic bacteria in the gastrointestinal tract, and finally be excreted from the body with feces. According to Spring (1993), manno-oligosaccharides can reduce the adhesion of Salmonella and Escherichia coli in the intestines of broilers. Sisak (1994) added 0.1% manno-oligosaccharides to the diet, and the detection rate of Salmonella in the abdomen and carcass of broilers decreased by 58% and 56% respectively. Spring (2000) reported that manno-oligosaccharides can enhance the immune response of pigs to Salmonella, hemolytic Escherichia coli and Campylobacter.

A large number of studies have shown that manno-oligosaccharides, as a feed additive, can activate the immune response of animals, increase the daily weight gain and feed conversion rate of broilers, turkeys, weaned piglets and calves, and reduce the incidence and mortality of gastrointestinal diseases. The experiments of van der (1997) and Dvorak (1998) have shown that manno-oligosaccharides can increase the daily weight gain and feed conversion rate of piglets, which may be due to their improved

The application effects of manno-oligosaccharides in animal production vary due to the following reasons: different animal species, age and condition of cattle; different purity, aggregation and physiological activity of manno-oligosaccharides. Differences in experimental conditions and addition amounts, as well as the use of basal diets and additives were not included in the experiment.