Direct intake of animal feed enzymes
has many health effects:
(1) Supplementation of endogenous enzymes (mainly digestive enzymes such as amylase, protease, lipase, etc.) and activation of endogenous enzymes secretion. Supplementary endogenous enzymes are suitable for young animals, such as suckling pigs and piglets.
(2) Hydrolysis of non-starch polysaccharides (NSP) and other anti-nutritional factors to reduce the viscosity of digestive tract contents. With the increase of viscosity, the diffusion rate of solute decreased, and the dissolution rate of nutrients from the diet was slowed down. With the increase of viscosity, the ability of intestinal mechanical mixtures was seriously hindered.
(3) It can destroy plant cell wall, release nutrients wrapped in cells, increase the contact surface with digestive enzymes, and improve digestibility and absorption.
(4) It can improve the body metabolic level and immunity. Recent studies have shown that animal feed enzymes
are not only directly involved in nutrient digestion and absorption, but also affect their metabolism and participate in the regulation of related hormones. In 1996, it was reported that adding 0.1% crude enzymes to Barley Diet to broilers increased insulin level in blood (p < 0.05) and decreased glucagon level, which indicated that enzymes could improve immunity of chickens. A school trial in Canada showed that the addition of enzymes significantly reduced mortality (11.3% to 4%) and primary osteoporosis (5.3% to 0.7%) in broilers.
(5) It can change the digestive site. Water-soluble non-starch polysaccharides in feed can increase water content, viscosity and emptying rate of chyme, promote microbial fermentation in hindgut, and reduce nutrient utilization rate. Addition of exogenous enzymes can change digestive sites, transfer digestive sites of some substances from cecum to small intestine, reduce microbial fermentation in hindgut, and improve digestibility. In addition, exogenous enzymes can also help improve the internal environment of the digestive tract, such as balancing the secretion of endogenous enzymes and reducing the shedding of intestinal mucosal cells.
(6) It can change the intestinal wall structure and improve nutrient absorption capacity. The small intestine jejunum is considered to be the main place where livestock and poultry digest and absorb nutrients. It was found that compared with the control group, and the length of villus in small intestine jejunum and ileum increased significantly at 0-3 weeks of age, which increased the area of nutrient absorption and enhanced the absorption capacity.