Comparison of corn-based and Canadian pearl millet-based diets on performance, digestibility, villus morphology, and digestive microbial populations in broiler chickens

A study was undertaken to examine the effects of partially or totally replacing corn with pearl millet in broiler diets on growth performance, jejunal digesta viscosity, and histomorphological parameters, ileal CP digestibility, and cecal microbial populations. Two hundred 1-d-old male Ross 508 broilers were randomly assigned to 1 of 5 isonitrogenous and isocaloric dietary treatments (8 cage replicates; 5 birds/cage) and grown over a 42-d experimental period. Dietary treatments included a standard corn-soybean meal diet and one in which the total amount of grain (corn + pearl millet) consisted of 25, 50, 75, or 100% pearl millet. All diets contained chromic oxide (0.4%) as an indigestible marker. Body weight and feed intake were recorded weekly throughout 42 d. At d 14, 28, and 42, 8 birds/treatment (1 bird/cage) were killed for sample collection and analysis. In comparison with corn, pearl millet grain contained higher CP (14.48 vs. 7.35%, on a DM basis) but slightly lower ME (3,093 vs. 3,355 kcal/kg, on a DM basis). Total replacement of corn by pearl millet significantly (P < 0.05) improved BW and feed conversion. Moreover, in comparison with the standard diet, feeding broilers pearl millet-based diets had no detrimental effects on digesta viscosity, villus height, villus width, and villus surface area of the jejunum. Ileal CP digestibility and cecal concentrations of Escherichia coli, lactobacilli, and bifidobacteria were also similar between birds fed corn and pearl millet. It was concluded that substituting corn for pearl millet in broiler diets can improve production responses without causing any adverse effects on nutrient digestibility or bird health.