Comparison of Intestinal Permeability Methods in Broilers over a 6-Week Growth Period

The adoption of methods detecting intestinal permeability in poultry has been slow due to the lack of urine availability in avian species. The objective of this study was to examine intestinal permeability assays in broilers using serum. Fluorescein isothiocyanate-dextran (FITC-D) and lactulose/mannitol/sucralose (LMS), indigestible sugars, were used to detect intestinal permeability across two fed states (fed or fasted) and four sugar treatments (Control, FITC-D, LMS, or FITC-D+LMS). Broilers housed in pens were assigned one of eight treatments and sampled on 14, 28, and 42 days of age. Data were analyzed using PROC Glimmix for fed state, sugar treatment, age, and all interactions. Serum lactulose and FITC-D increased in fasted compared to fed birds (p < 0.006), whereas mannitol increased in fed compared to fasted birds (p < 0.001). Serum lactulose and FITC-D decreased on day 28 compared to other timepoints (p < 0.003). Serum FITC-D only had a significant sugar by fed state interaction (p < 0.05) with elevated concentrations in fasted and fed birds that received FITC-D. Serum lactulose was significant for all interactions with elevated concentrations in broilers provided lactulose and fasted (p < 0.001). The ability to detect a three-way interaction with serum lactulose suggests an increased sensitivity; however, additional studies are needed.