The effects of dietary non-starch polysaccharides on Ascaridia galli infection in grower layers

This study examined whether Ascaridia galli infection can be controlled by dietary non-starch polysaccharides (NSP) in chickens. One-day-old chicks were fed either a basal diet (CON) or CON plus insoluble NSP (I-NSP), or CON plus soluble NSP (S-NSP) for 11 weeks. Three weeks later, birds from half of each feeding group were inoculated with 250 embryonated eggs of A. galli, and slaughtered 8 weeks post-infection to determine worm counts. Both NSP diets, particularly S-NSP, increased prevalence of infection (P<0.05) and worm burden (roughly +50%) of the birds (P<0.001). A. galli infection caused a less efficient (P = 0.013) feed utilization for body weight gain (BWG) resulting in lower body weights (P<0.001) irrespective of type of diet consumed. NSP-fed birds, particularly those on I-NSP, consumed more (+ 8%) feed per unit BWG and showed retarded (P<0.001) BW development compared to CON-fed birds. Intracaecal pH was lowered by S-NSP (P<0.05). Both NSP diets increased the volatile fatty acids pool size in caeca (P<0.001) with S-NSP exerting a greater effect (+ 46%) than I-NSF (+ 24%). It is concluded that both NSPs supplemented diets alter gastrointestinal environment in favour of the nematode establishment, and thus have no potential for controlling A. galli infection in chickens.