The objective of this study was to assess the effects of dietary inulin supplementation on growth performance
and intestinal immune parameters of broilers. A total of 280 one-day-old Cobb 500 male broilers
were randomly allocated into four groups of seven replicate pens and given a maize-soybean basal diet
supplemented with 0, 5, 10 and 15 g/kg of inulin during the 42 days of the experiment. Feed intake (FI),
body weight gain (BWG) and feed conversion ratio (FCR) were determined from d 1 to 21 (starter), and
from d 22 to 42 (grower). Intestinal T lymphocyte subpopulations, the production of immunoglobulin A
(IgA) and cytokines as well as mucin mRNA expression were measured at 21 d and 42 d. Feed intake was
increased quadratically (P¼0.001) as the dietary inulin level increasing during starter period only. However
BWG and FCR of broilers were not affected by inulin supplementation in either period. At d 21 and as the
dietary inulin concentration increasing, proportion of T CD4þ T lymphocyte and CD4þ/CD8þ ratio in ileum
tissue tended (P¼0.05–0.087) to be linearly increased, IgA concentration in cecal content and mucin mRNA
expression in jejunum tissue were linearly increased (P¼0.006–0.01), whereas concentrations of interleuk-
6 and interferon-γ in ileum tissue quadratically (Po0.05) decreased. The effects of dietary inulin on these
intestinal immunological parameters were minimal at the 42-d age of broilers. These results indicated that
dietary inulin at the levels of 5–10 g/kg may have the beneficial effects on enhancing intestinal immune
function of broiler chicken at younger age when the intestinal function is not fully developed.
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