The Effects Of Non-starch Polysaccharides Enzyme On Growth Performance For Growing Pigs And Digestibilities Of Nutrients

The paper was conducted to study on the effects of non-starch polysaccharides (NSP) enzyme supplementations on growth performance, economic benefit, biochemical indexes of serum and nutrients digestibilities for growing pigs, and the effects of NSP enzyme on degradation of plant cell wall composition and generation of small molecules by pepsin-trypsin-dialysis in vitro digestion to explore the effects and mechanisms of NSP enzyme on growth performance of growing pigs and digestibilities of nutrients.In experiment 1:The 224-growing pigs weighing 30±1.2 kg were chosed and allocated to 1 of 4 treatments according to their BW with 4 replicates per treatment and 14 pigs per replicate. The basal experimental diet was corn, wheat bran, soybean, rapeseed meal and cottonseed meal containing 3.1 MCal/kg and 16% CP. Growing pigs were fed basal diet, basal diet+0.01% NSP enzyme supplementations, basal diet +0.015% NSP enzyme supplementations and basal diet+0.02% NSP enzyme supplementations. The growth trail lasted for 35 days. When it was the last week for growth trial, the degestibility trail started and lasted for 7 days.The results showed that:1. Pigs fed NSP enzyme-supplemented diets had a higher growth performance and lower weight gain costs than those fed the control diet. Pigs fed diets supplemented with 0.01%,0.015% and 0.02% NSP enzyme appeared higher ADG and lower F/G (P< 0.05)than those fed the control diet, adding 0.015% NSP enzyme worked best.2. Compared with control, NSP enzyme supplementations increased apparent total tract digestibilities (ATTD) of DM, energy, CP, NDF, ADF, hemicellulose (P<0.05). ATTD of NDF and hemicellulose increased with NSP enzyme added. And adding 0.015% NSP enzyme had the highest ATTD of DM, energy, CP and ADF. 3. NSP enzyme supplementations improved growth performance by mainly increasing energy and hemicellulose digestibilities. The stepwise regression of apparent nutrients digestibilities and growth performance indicators showed that ATTD of energy had maximum correlation with ADG (R2=0.628, P<0.05), and ATTD of energy and hemicellulose had maximum correlation with F/G (R2=0.805, P<0.05).4. The NSP enzyme supplementations affected blood biochemical parameters of growing pigs for different degree. The NSP enzyme preparations in diets had no significant effect on total protein, albumin, globulin in serum of growing pigs (P>0.05), but increased glucose, T3 content and the ratio of T3 and T4, and decreased urea nitrogen content.In experiment 2:The pepsin-trypsin-dialysis in vitro digestion techniques was used to study the in vitro digestibilities of nutrients and the production of reducing sugar and monosaccharides in feed with different levels of NSP enzyme supplementations. The trial had 4 treatments with 8 replicates per treatment. The diets and enzyme supplementations were the same as experiment 1.The results showed that:1. The in vivo digestibilities of nutrients were predicted by the in vitro digestion technique. The in vitro digstibilities of energy (R2=0.691, P< 0.05), dry matter (R2=0.256, P< 0.05), NDF (R2=0.256, P< 0.05) and hemicellulose (R2=0.256, P< 0.05) were correlated with their ATTD.2. Adding different levels of NSP enzyme increased the in vitro digestibilities of nutrients. The diet with 0.015% NSP enzyme supplementation significantly increased in the in vitro digestibilities (IVD) of DM, CP, NDF, ADF, total arabinoxylans, soluble arabinoxylan, pectin, hemicellulose and cellulose compared to the control (P<0.05). The IVD of DM and soluble arabinoxylans of the diet with 0.015% NSP enzyme supplementation were higher than those of 0.01% NSP enzyme supplementation and 0.02% NSP enzyme supplementation (P<0.05). Enzymes-supplemented diets did not improve the IVD ofβ-glucan over control diet (P>0.05).3. NSP enzyme increased obviously degradation of cell wall, especially the arabinoxylans. 4. The NSP enzyme preparations in diets improved NSP degradation and conversion. The largest formation of arabinose, xylose, glucose and reducing sugar was the diet with 0.015% NSP enzyme supplementation, which of a-galactose was the diet with 0.02% NSP enzyme supplementation.In conclusion, the diets supplemented with NSP enzyme had effects on improving digestion and nutrients digestion and utilization of cell wall and other nutrients. The effects of NSP enzyme were due to its ability to increase energy through the promotion of cell wall (hemicellulose is the most important) degradation and conversion, thereby enhancing growth performance of growing pigs. This is a good channel for economic and effective usage of inferior feeds that pigs fed the diet containing corn, wheat bran, soybean meal, rapeseed meal and cottonseed meal supplemented with 0.015% of NSP enzyme supplementations.