Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against pathogenic infection, according to T.A. Faber of the University of Illinois, Urbana and co–authors there and at Temple–Inland in Diboll, Texas and the National Center for Agricultural Utilization Research (NCAUR), part of the USDA Agricultural Resarch Service in Peoria, Illinois.

In their paper published recently in Poultry Science, they hypothesised that a mannose–rich GGMO–AX complex would positively impact immune status and prevent weight loss resulting from acute coccidiosis (Eimeria acervulina) infection in chicks.

The researchers explained that the production of the GGMO–AX substrate involves use of wood chips, water and pressure but does not use strong acids or bases, unlike other fibre–board production processes. This results in an ingredient better tailored for consumption by animals. To obtain a dry product, the GGMO–AX syrup was spray–dried.

Using a completely randomised design, day–old commercial broiler chicks (n=160; four replications per treatment; five chicks per replication) were assigned to one of four corn–soybean meal–based diets containing supplemental GGMO-AX (0, 1.0, 2.0 or 4.0 per cent) that replaced dietary cellulose.

On day 9 post hatch, an equal number of chicks on each diet were inoculated with either distilled water (sham control) or E. acervulina (1×10⁶ oocysts). All birds were euthanised on day 7 post–inoculation (PI) for collection of caecal contents and duodenal tissue.

Overall, bodyweight gain of chicks was not affected by diet post–inoculation, whereas infection decreased (P<0.01) weight gain on day 0 to 7 post–inoculation.

Feed intake was not affected by dietary treatment but infection decreased (P<0.01) feed intake on days 0 to 7 post–inoculation. Overall, infection but not diet decreased (P<0.01) gain:feed ratio on day 0 to 7 post–inoculation.

Caecal propionate concentrations were independently affected by infection and diet, while butyrate concentrations were affected only by infection (P=0.02).

Caecal Bifidobacterium spp. populations were affected (P<0.01) by diet, with the 2.0 per cent GGMO–AX resulting in the highest count (colony–forming units per gram; cfu/g) of caecal contents on a dry matter basis.

Messenger RNA expression of all duodenal cytokines evaluated was affected by infection status (P=0.02) but not by dietary treatment alone.

Supplementing 4.0 per cent GGMO–AX consistently resulted in the greatest fold change in pro–inflammatory cytokine expression, while inhibiting anti–inflammatory cytokine expression, which indicates a more robust innate immune response.

Faber and co–authors concluded that, despite decreasing performance, four per cent dietary GGMO–AX improved select fermentation indices and the innate intestinal immune response to an acute E. acervulina infection.

Reference

Faber T.A., R.N. Dilger, A.C. Hopkins, N.P. Price and G.C. Fahey Jr. 2012. The effects of a galactoglucomannan oligosaccharide–arabinoxylan (GGMO–AX) complex in broiler chicks challenged with Eimeria acervulina. Poult. Sci. 91(5):1089-1096. doi: 10.3382/ps.2011-01993

Further Reading

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Further Reading

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Find out more information on coccidiosis by clicking here.

June 2012