The present study investigated whether supplementing fibre-degrading enzymes can ameliorate the severity of subclinical necrotic enteritis(NE)in broiler chickens offered wheat-or maize-based diets.A total of 1,544 mixed-sex broiler chickens were assigned to 16 experimental treatments as a 2×2×4 factorial arrangement of treatments.The factors were the following:NE challenge,yes or no;diet type,wheat-or maize-based;and enzyme supplementation,control(no enzyme),family 10 xylanase(XYN10),family 11 xylanase(XYN11)or β-mannanase(MAN).Each treatment was replicated 6 times,with 16 birds per replicate pen.A three-way challenge x diet type x enzyme interaction occurred for body weight at 21 d of age(P=0.025)and overall feed conversion ratio(P=0.001).In the non-challenged birds fed the wheat-based diet,supplementing MAN increased d 21 body weight compared to the control.In chal-lenged birds fed the maize-based diet,supplemental XYN11 impeded body weight and overall FCR compared to the control.Birds offered the maize-based diet presented heavier relative gizzard weights at both 16 and 21 d of age(P＜0.001)and reduced liveability(P=0.046)compared to those fed the wheat-based diet.Enzyme supplementation reduced ileal and jejunal digesta viscosity at 16 d of age only in birds fed the wheat-based diet(P＜0.001).XYN11 increased ileal digesta viscosity in birds fed the maize-based diet,and MAN reduced it in birds fed the wheat-based diet at 21 d of age(P=0.030).Supple-menting XYN11 improved ileal soluble non-starch polysaccharides(NSP)digestibility in birds fed the wheat-based diet compared to non-supplemented birds(P＜0.001).Birds fed the wheat-based diet displayed a higher abundance of Bifidobacterium,Lactobacillus and Enterobacteriaceae and butyric acid in the caeca at 16 d of age compared to birds fed the maize-based diet(P＜0.05).In conclusion,supple-mental XYN11 exacerbated the negative impact of NE on growth performance in birds fed the maize-based diet.Supplementing wheat-based diets with fibre-degrading enzymes ameliorates production losses induced by NE.

Eunjoo Kim;Amy F.Moss;Natalie K.Morgan;Kosar Gharib-Naseri;Peter Ader;Mingan Choct

School of Environmental and Rural Science,University of New England,Armidale,NSW 2351,Australia;BASF SE,68623,Lampertheim,Germany

动物营养（英文）

[1]Eunjoo Kim;Amy F.Moss;Natalie K.Morgan;Kosar Gharib-Naseri;Peter Ader;Mingan Choct-.Non-starch polysaccharide-degrading enzymes may improve performance when included in wheat-but not maize-based diets fed to broiler chickens under subclinical necrotic enteritis challenge)[J].动物营养（英文）,2022(03):54-67

XYN10,XYN11,mannanase,lenged,gizzard,liveability,digesta

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