The Interaction Effects Of Soybean Meal And β-mannanase On Growth Perforamnce And Serum Physiological And Biochemical Indices Of Weaner Piglets

The galactomannan（GM）in soybean meal（SBM）has adverse effect on animal physiology.β-1,4-Glycosidic bond in GM can be decomposed byβ-mannanase（β-MN）and GM can be hydrolyzed to mannose-oligosaccharides and other small molecules.This experiment analyzed the content ofα-GM,β-GM and GM in 22 kinds of dietary raw materials,using soybean mealα-GM,β-GM and GM as main sources,designed two gradients SBM（22%and 37%）for weaning piglets and the diets supplemented byβ-MN,this study evaluated the interaction effects of SBM andβ-MN on the growth performance,serum content ofα-GM,β-GM,and GM,biochemical indices,amino acid,viscera index,intestinal morphology and the gene expressions of AQPs and the amino acid transporters of weaner piglets,to provide the basis for the practial application of pig raising.One hundred healthy dualistic male weaner piglets（castrated male piglets）with about 9 kg of average body weight were randomly divided into four groups（Ⅰ,Ⅱ,Ⅲ,Ⅳ）with 25 pigs per group in a 2×2 factorial design.TheⅠgroup was control group（22%of SBM）.Ⅱgroup（22%SBM+0.02%β-MN）,Ⅲgroup（37%SBM）,Ⅳgroup（37%SBM+0.02%β-MN）were experimental groups.The experiment lasted for 30 days.During the test period,the average daily intake was recorded and the diarrhea index was recorded according to fecal status,and weighed 100 weaner piglets on the 1 d,14 d and 30 d.At the30^th day of the trial period,seven weaner piglets were selected from each group,and 28piglets were sampled for anaesthetic slaughter.10 mL blood samples from carotid artery,mesenteric vein,and portal vein were collected respectively forα-GM,β-GM,and GM,biochemical and amino acid analysis.The proximal jejunum and distal ileum samples were collected for analysis of intestinal morphology and the gene expressions of AQPs and amino acid transporters.1.The effects of SBM level andβ-MN on the growth performance of piglets:compared with 22%SBM diet,increasing SBM level to 37%significantly increased the fecal score（P<0.05）.SBM andβ-MN have the interaction effects on ADG（P<0.05）,G:F（P<0.05）and fecal score（P<0.05）in 1-14 d.Compared with 22%SBM diet,increasing SBM level to 37%significantly decreased the ADG（P<0.05）and increased the fecal score（P<0.05）of weaner piglets.Compared with unaddedβ-MN group,adding 0.02%β-MN significantly increased the ADG（P<0.05）and ADFI（P<0.05）.SBM andβ-MN have the interaction effects on ADG（P<0.05）,ADFI（P<0.05）and G:F（P<0.05）from 15 d to 30 d.Compared with 22%SBM diet,increasing SBM level to 37%significantly increased the fecal score（P<0.05）.Compared with unaddedβ-MN groups,adding 0.02%β-MN significantly increased the ADG（P<0.05）.SBM andβ-MN have the interaction effects on ADG（P<0.05）,G:F（P<0.05）,final weight（P<0.05）,fecal score（P<0.05）of weaner piglets in 1-30 d.2.The effects of SBM level andβ-MN on the viscera index and the intestinal morphology of piglets:compared with 22%SBM diet,increasing SBM level to 37%significantly decreased the liver index（P<0.05）.Compared with unaddedβ-MN group,adding 0.02%β-MN significantly increased the liver index（P<0.05）.In jejunum,compared with 22%SBM diet,increasing SBM level to 37%significantly decreased the villus height（P<0.05）;compared with unaddedβ-MN group,adding 0.02%β-MN increased the villus height（P<0.05）and the ratio of villus height and the crypt depth（P<0.05）.In ileum,compared with 22%SBM diet,increasing SBM level to 37%decreased the villus height（P<0.05）and the ratio of villus height and the crypt depth（P<0.05）.SBM andβ-MN have the interaction effects of crypt depth（P<0.05）and the ratio of villus height and the crypt depth（P<0.05）.3.The effects of SBM level andβ-MN on the content of serum biochemical,GM and amino acid of piglets:in carotid artery,compared with unaddedβ-MN group,adding0.02%β-MN improved the content of C4（P<0.05）,Trp（P<0.05）,and decreased the content ofα-GM（P<0.05）andβ-GM（P<0.05）in the serum of piglets.Compared with22%SBM diet,increasing SBM level to 37%increased the content ofα-GM（P<0.05）,β-GM（P<0.05）,GOT（P<0.05）and BUN（P<0.05）and decreased the content of Arg（P<0.05）,Asp（P<0.05）,Glu（P<0.05）,Thr（P<0.05）,Cys（P<0.05）,Tyr（P<0.05）,Met（P<0.05）,Val（P<0.05）,Ile（P<0.05）,Leu（P<0.05）.In mesenteric vein,compared with unaddedβ-MN group,adding 0.02%β-MN significantly decreased the content ofα-GM（P<0.05）,ALT（P<0.05）,GOT（P<0.05）,BUN（P<0.05）,CREA（P<0.05）,and increased the content of His（P<0.05）,Gly（P<0.05）,Asp（P<0.05）,Glu（P<0.05）,Trp（P<0.05）,Ca（P<0.05）.Compared with 22%SBM diet,increasing SBM level to 37%increased the content ofα-GM（P<0.05）,β-GM（P<0.05）,GM（P<0.05）,CREA（P<0.05）,Ca（P<0.05）,P（P<0.05）,and decreased the content of Arg（P<0.05）,Thr（P<0.05）,Lys（P<0.05）,Tyr（P<0.05）,Met（P<0.05）,Ca（P<0.05）,P（P<0.05）.In portal vein,compared with unaddedβ-MN group,adding 0.02%β-MN decreased the content ofα-GM（P<0.05）,GM（P<0.05）,BUN（P<0.05）and increased the content of His（P<0.05）,Gly（P<0.05）,Asp（P<0.05）,Trp（P<0.05）.Compared with 22%SBM diet group,increasing SBM level to 37%increased the content ofα-GM（P<0.05）,β-GM（P<0.05）,GOT（P<0.05）,Arg（P<0.05）,Thr（P<0.05）,Lys（P<0.05）,Tyr（P<0.05）,Met（P<0.05）.β-MN and SBM have the interaction effect on the content of GOT（P<0.05）in carotid artery,the content of GOT（P<0.05）,CREA（P<0.05）,CA（P<0.05）in mesenteric vein,and the content of ALT（P<0.05）,GOT（P<0.05）in portal vein.Increasing SBM level to 37%broke the physiological biochemical and amino acid balance and reduce the health condition of piglets.β-MN can regulate the amino acid balance,meet the needs of amino acids of the piglets.4.The effects of SBM level andβ-MN on gene expressions of AQPs and amino acid transporters of piglets showed that:compared with unaddedβ-MN group,adding 0.02%β-MN improved the gene expressions of AQP8（P<0.05）,AQP10（P<0.05）,SLC7A1（P<0.05）,SLC7A11（P<0.05）and SLC38A2（P<0.05）in jejunum and increased the content of AQP3（P<0.05）,AQP11（P<0.05）,SLC6A9（P<0.05）,SLC36A1（P<0.05）in ileum.Compared with 22%SBM diet,increasing SBM level to 37%reduced the gene expressions of AQP3（P<0.05）,AQP8（P<0.05）,AQP11（P<0.05）,SLC1A5（P<0.05）,SLC7A1（P<0.05）in ileum.The above results showed that:weaned piglet dietary SBM levels reached 37%can decrease the growth performance and break the amino acid balance in piglets.The content ofα-GM,β-GM and GM in serum are increased by the dietary ofα-GM,β-GM and GM content increase.Adding 0.02%β-MN in diet can decrease the content of GM in serum and regulate serum physiological and biochemical indices,maintaine the balance of amino acids in serum,and improve the relative expression of AQPs and amino acid transporters.