Arabinoxylan （AX） content in barley grains is an important quality determinant when barley is used as raw material of malt or beer production. The cultivar and environmental variations of total arabinoxylan （TAX）,...Arabinoxylan （AX） content in barley grains is an important quality determinant when barley is used as raw material of malt or beer production. The cultivar and environmental variations of total arabinoxylan （TAX）, water extractable arabinoxylan （WEAX） and endoxylanase activity （EA） were investigated using eight barley cultivars growing at seven locations with diverse environmental conditions. The results showed that both barley cultivar and location significantly affected the TAX, WEAX and EA levels, but the variations of TAX content and EA were mainly attributed to cultivar, while the impact of location on WEAX content was greater than that of cultivar. Correlation analysis indicated that TAX was significantly correlated to WUAX.展开更多
Despite the general use of endoxylanases in poultry feed to improve broiler performance,the abundance of different endoxylanase products and the variable response to their application in the field prevent a clear unde...Despite the general use of endoxylanases in poultry feed to improve broiler performance,the abundance of different endoxylanase products and the variable response to their application in the field prevent a clear understanding of endoxylanase functionality in vivo.To gain insight into this functionality,we investigated the impact of endoxylanase type(Belfeed from Bacillus subtilis versus Econase XT from Nonomuraea flexuosa)and dose(10,100,1,000 mg/kg)in combination with broiler age on arabinoxylan(AX)hydrolysis and fermentation in broilers(Ross 308)fed a wheat-soy based diet.In a digestibility trial and a performance trial,a total of 1,057 one-day-old chicks received the control diet or 1 of the 6 endoxylanase supplemented wheat-soy based diets with,respectively,5 replicate cages and 8 replicate pens per dietary treatment per trial.The AX content and structure,the AX digestibility values and the short-chain fatty acids produced were analysed at the level of the ileum,caeca and excreta at d 11 and 36.Endoxylanase supplementation resulted in a more extensive solubilisation of wheat AX and a reduction in the intestinal viscosity compared to the control(P<0.05).A high endoxylanase dose was,however,required to obtain increased hydrolysis of the dietary AX along the gastrointestinal tract against the control(P<0.001).Depending on the type of endoxylanase,a pool of AX with distinct physicochemical properties was created.The B.subtilis endoxylanase created a large pool of soluble AX in the ileum,thereby increasing ileal viscosity compared to broilers fed an endoxylanase from N.flexuosa(P<0.001).The N.flexuosa endoxylanase mainly triggered caecal AX fermentation in young broilers,by delivering easily fermentable AX substrates with a low degree of polymerisation(P=0.03).The effects were particularly present in young broilers(d 11).From this study,it is clear that the type and dose of endoxylanase added to wheat-soy based diets determine the nature of AX substrates formed.These,in turn,affect the intestinal viscosity and the interplay between the dietary AX compounds and microbiota,hence dictating AX digestion at young broiler ages and performance outcomes towards slaughter age.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province,China(Y3100074)the Social Development Scientific Research Project,Hangzhou Science and Technology Bureau,China(20100933B08)
文摘Arabinoxylan （AX） content in barley grains is an important quality determinant when barley is used as raw material of malt or beer production. The cultivar and environmental variations of total arabinoxylan （TAX）, water extractable arabinoxylan （WEAX） and endoxylanase activity （EA） were investigated using eight barley cultivars growing at seven locations with diverse environmental conditions. The results showed that both barley cultivar and location significantly affected the TAX, WEAX and EA levels, but the variations of TAX content and EA were mainly attributed to cultivar, while the impact of location on WEAX content was greater than that of cultivar. Correlation analysis indicated that TAX was significantly correlated to WUAX.
文摘Despite the general use of endoxylanases in poultry feed to improve broiler performance,the abundance of different endoxylanase products and the variable response to their application in the field prevent a clear understanding of endoxylanase functionality in vivo.To gain insight into this functionality,we investigated the impact of endoxylanase type(Belfeed from Bacillus subtilis versus Econase XT from Nonomuraea flexuosa)and dose(10,100,1,000 mg/kg)in combination with broiler age on arabinoxylan(AX)hydrolysis and fermentation in broilers(Ross 308)fed a wheat-soy based diet.In a digestibility trial and a performance trial,a total of 1,057 one-day-old chicks received the control diet or 1 of the 6 endoxylanase supplemented wheat-soy based diets with,respectively,5 replicate cages and 8 replicate pens per dietary treatment per trial.The AX content and structure,the AX digestibility values and the short-chain fatty acids produced were analysed at the level of the ileum,caeca and excreta at d 11 and 36.Endoxylanase supplementation resulted in a more extensive solubilisation of wheat AX and a reduction in the intestinal viscosity compared to the control(P<0.05).A high endoxylanase dose was,however,required to obtain increased hydrolysis of the dietary AX along the gastrointestinal tract against the control(P<0.001).Depending on the type of endoxylanase,a pool of AX with distinct physicochemical properties was created.The B.subtilis endoxylanase created a large pool of soluble AX in the ileum,thereby increasing ileal viscosity compared to broilers fed an endoxylanase from N.flexuosa(P<0.001).The N.flexuosa endoxylanase mainly triggered caecal AX fermentation in young broilers,by delivering easily fermentable AX substrates with a low degree of polymerisation(P=0.03).The effects were particularly present in young broilers(d 11).From this study,it is clear that the type and dose of endoxylanase added to wheat-soy based diets determine the nature of AX substrates formed.These,in turn,affect the intestinal viscosity and the interplay between the dietary AX compounds and microbiota,hence dictating AX digestion at young broiler ages and performance outcomes towards slaughter age.
