The flow of non-starch polysaccharides along the gastrointestinal tract of broiler chickens fed either a wheat- or maize-based diet

The present study characterised the types and amounts of non-starch polysaccharides (NSP) remaining undigested along the gastrointestinal tract (GIT) of broiler chickens offered a typical wheat-or maize based diet. One-day old Cobb 500 mixed-sex chicks were assigned to 24 pens, with 10 birds/pen and 12 pens/treatment. Birds were offered the experimental diets in 3 phases (starter, day 0 to 10; grower, day 11 to 24 and finisher, day 25 to 35). Excreta and digesta samples from the crop, gizzard, duodenum, jejunum, ileum and caeca were collected at 12 and 35 days of age, and analysed for the NSP flow. The wheat-based diet contained higher levels of soluble NSP than the maize-based diet, whereas insoluble NSP levels were similar between the 2 diets. Detailed analysis of NSP constituents revealed that arabinoxylans were the primary NSP in the wheat-based diet, mostly in insoluble form. Pectins were the predominant NSP in the maize-based diet, followed by arabinoxylans. Overall, birds offered the wheat based diet presented higher levels of soluble NSP remaining in all gut sections compared to birds offered the maize-based diet, at both 12 and 35 days of age (P < 0.050). Accumulation of insoluble NSP in the gizzard was noted in birds fed both diets, but was more pronounced in birds offered the maize-based diet compared to the wheat-based diet, at both 12 and 35 days of age (P < 0.001). The present study highlights marked differences in the amounts and types of NSP delivered to the different gut sections when feeding wheat-compared to maize-based diets, particularly in the gizzard and the lower GIT of birds. ?? 2022 Chinese Association of Animal Science and Veterinary Medicine. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study characterized the types and amounts of undigested non-starch polysaccharides (NSP) along the gastrointestinal tract in broiler chickens fed a typical wheat or maize-based diet. The results showed that the wheat-based diet had higher levels of soluble NSP compared to the maize-based diet, while the levels of insoluble NSP were similar between the two diets. Arabinoxylans were the primary NSP in the wheat-based diet, mainly in insoluble form, while pectins were the predominant NSP in the maize-based diet. Birds fed the wheat-based diet had higher levels of soluble NSP in all gut sections compared to those fed the maize-based diet, and there was a higher accumulation of insoluble NSP in the gizzard of birds fed the maize-based diet.