Influence of Whole Grain Diets on Glycemic Response Indices and Whole Tract Transit Time in Broiler Chicken

Abstract

The influence of whole millet grain feeding on (a) starch digestion and glucose absorption, (b) digesta residence time in the gastrointestinal tract, and (c) relationship between glycemic response and digesta residence time in broiler chicken was assessed in this study. A total of 360 1-day-old broiler chicks of a commercial breed (Arbor- acre) were randomly allotted to 6 treatment groups of 5 replicates, 12 chicks per replicate. Chicks were fed diets containing 0, 20, 40, 60, 80, or 100% whole millet replacement for milled millet in broiler starter diets with supplemental phytase for 28 days. On d-21, blood was drawn from fasted chicken (2 per replicate) before feeding and at intervals up to 4.5 hours postprandial to assess glycemic response. On d-28, whole tract transit time was assessed by feeding the experimental diets containing 1% chromic oxide to fasted chicken and observing time lapse until coloured excreta was observed. Whole millet in the diets had no effect on mean glucose concentration; mean incremental glucose concentration, time at peak glucose concentration and whole tract transit time. Higher whole millet inclusions i.e. W80 and W100, recorded lower area under the curve (AUC) values (1103.76 ± 67.85 and 1111.98 ± 78.20 mg dL^-1. h^-1 respectively) with highest AUC observed in W0 (1190.40 ± 79.42 mg dL^-1. h^-1). However area under the incremental curve was not influenced by whole millet inclusion in the diets. In conclusion, whole millet inclusion in the diets of broiler chickens did not affect starch digestion, glucose absorption or digesta residence within the gastrointestinal tract.