Effects of mannan level and β-mannanase supplementation on growth performance, apparent total tract digestibility and blood metabolites of growing pigs

Abstract

The exogenous enzymes are less consistent in their effects as their beneficial effects depend upon the types and level non-starch polysaccharides (NSP) present in the diets. Therefore, exogenous enzymes should be selected on the basis of types and amount of the NSP in the pig diets. The objectives of the present experiments were to investigate the effects of dietary level of mannan and β-mannanase supplementation on growth performance, apparent total tract digestibility (ATTD) of energy and nutrients, and blood metabolites of growing pigs. In Exp. 1, 96 barrows were randomly allotted to four treatments on the basis of BW. There were four replicates in each treatment with six pigs per replicate. The dietary treatments were a corn-soybean meal (SBM)-based control diet and three other diets consisted of the control diet supplemented with 400, 800 or 1600 U of β-mannanase/kg diet. The final BW, average daily gain (ADG) and blood glucose increased (linear, P < 0.05) with increasing concentrations of dietary β-mannanase. The ATTD of dry matter (DM), gross energy (GE) and β-mannan was higher (linear, P < 0.05) with increase in dietary β-mannanase concentrations. In Exp. 2, 288 barrows were allotted to six treatments in a 2 × 3 factorial arrangement of mannan level (high v. low) and addition of β-mannanase (0, 400 or 800 U/kg diet). There were four replicates in each treatment with 12 pigs/replicate. Pigs were fed corn-SBM-based low-mannan diet (6.1 g/kg) or high-mannan (25.2 g/kg) diet in which corn and SBM were partially replaced with 50 g/kg diet palm kernel meal. All diets were fed in meal form for 42 days. Pigs fed diets supplemented with β-mannanase had greater ( P < 0.05) final BW, ADG, feed to gain (F : G), the ATTD of DM, GE, and β-mannan and blood glucose concentration compared with pigs fed diets without β-mannanase. In addition, the final BW, ADG, F : G and the ATTD of GE and β-mannan were reduced ( P < 0.05) in low mannan level. The dietary level of mannan and the β-mannanase supplementation had no effects ( P > 0.05) on the concentrations of blood total cholesterol, triacylglycerides and blood urea nitrogen. These results indicate that supplementation of β-mannanase to low-or high-mannan diets have potential to improve the performance of growing pigs. In addition, palm kernel meal may partially replace corn and SBM without reducing pig performance if β-mannanase is added to diet.Keywords: blood metabolites, growing pigs, performance, mannan, β-mannanase ImplicationsThe β-mannan accounts for 15% to 35 % (soy-based to palm-based) of total non-starch polysaccharides content of the pig diets, β-galactomannan, is a polysaccharide with repeating units of mannose, with galactose or glucose, or both, often found attached to the β-mannan. Pig digestive tract lacks the enzymes targeting β-1, 4-mannosyl bond and α-1, 6-galactosyl bonds, which limits the nutrient utilization and growth performance. These results indicate that β-mannanase have potential to improve the performance of growing pigs, and palm kernel meal m...

A dose–response study to evaluate the effects of pH-stable β-mannanase derived from Trichoderma citrinoviride on growth performance, nutrient retention, and intestine morphology in broiler chickens

“…High NSP content in broiler chickens diets decrease the accessibility by impairing the mixing of digestive enzymes with substrates by increasing viscosity of digesta (Lee et al 2003;Montagne et al 2003). Exogenous NSP enzymes in poultry diets has been widely reviewed and well documented to decrease the digesta viscosity and increase nutrient digestibility (Lee et al 2003;Ryu et al 2017;Kim et al 2017). The greater nutrients retention in the present study may be related to improvements of digesta viscosity, effective degradation of nondigestible NSP and greater intestinal villus height.…”

“…There are two hypotheses for the enzymatic influences of b-mannanase on the retention of nutrients. First, the role of enzyme on the breaking the bonds between the sub-units in NSP to decrease the viscosity of digesta and release the encompassed nutrients in their complex structure (Lee et al 2003;Kim et al 2017;Senkoylu et al 2009). Another reason may be associated to the usage of the released NSP monomers such as arabinose, mannose, galactose, and glucose as nutrients.…”

“…The complex molecular structure of b-mannan consist of b-1,4-mannopyranosyl residues or mannose residues (Buckeridge 2010). The low nutrient digestibility and growth performance in monogastrics is due to the lack of proper enzyme to cut the bonds in b-mannan (Kim et al 2017). The greater growth performance and nutrient digestibility have observed by breaking the bonds in mannans by supplementing b-mannanase or enzyme complex to the diet of broiler chickens (Shim et al 2017b), laying hens (Shim et al 2017a;Ryu et al 2017) or pigs (Kim et al 2017(Kim et al , 2018.…”

“…The low nutrient digestibility and growth performance in monogastrics is due to the lack of proper enzyme to cut the bonds in b-mannan (Kim et al 2017). The greater growth performance and nutrient digestibility have observed by breaking the bonds in mannans by supplementing b-mannanase or enzyme complex to the diet of broiler chickens (Shim et al 2017b), laying hens (Shim et al 2017a;Ryu et al 2017) or pigs (Kim et al 2017(Kim et al , 2018. Many factors such as type of the substrate, the amount of dietary NSP content and physiological status of animals affect the response of exogenous enzymes on performance.…”

“…One of the approaches to improve the nutritional value of diets is dietary exogenous enzyme supplementation to degrade the structure of anti-nutrients (Kim et al 2018). The supplementation enzymes in to broiler chickens diet has been extensively reviewed and well documented to enhance the growth performance and feed efficiency (Shim et al 2017b;Kim et al 2017Kim et al , 2018. However, the inability of enzymes to tolerate the high temperature of pelleting during feed processing and low pH of stomach may be contributed to the inconsistent reported results in the literatures.…”