Effects of select tannin-free grain sorghum varieties on the performance, carcass traits, intestinal morphology, and gene expression of jejunal mucosa of broiler chickens

Abstract

Objective: The objective of this study was to evaluate the effects of tannin-free grain sorghum varieties on the performance, carcass traits, intestinal morphology, and gene expression of broiler chickens. Materials and Methods: Cobb 500 × Hubbard male broilers (n = 640, 20 birds per pen, 8 pens per treatment) were fed diets based on corn, red/bronze, white/tan, or US No. 2 in crumble/pellet presentation fed in starter, grower, and finisher phases. Group BW and feed intake were recorded weekly. Mortality was recorded daily for the calculation of adjusted feed conversion ratio. At 41 d, two birds per pen were selected for the average pen weight for carcass yield and breast yield values. The intestinal morphology using histology and change in transcription using mRNA-seq was compared among birds fed corn and those fed grain sorghum (1 bird per pen). Pen was considered the experimental unit with model effects assessed with ANOVA and Fisher's LSD procedure. Results and Discussion: Birds fed the corn treatment had greater BW gain (P = 0.009; 3,622, 3,479, 3,518, and 3,483 g for corn, red/bronze, white/tan, and US No. 2 sorghum diets, respectively) at 41 d. Feed intake was greatest for birds fed corn and red/bronze diets (5,495 and 5,599 g, respectively) when compared with the white/tan diet (5,357 g), whereas US No. 2 sorghum-fed birds were intermediate (5,346 g; P = 0.005). Birds had improved adjusted feed conversion ratio in all treatments (P < 0.001; 1.52, 1.51, and 1.53 g:g for corn, white/tan, and US No. 2 sorghum diets, respectively) compared with red/bronze (1.60 g:g) at 41 d. No effects of grain sorghum treatments were observed on carcass traits and intestinal morphology. The mRNA-seq revealed 46 differentially expressed genes. Birds fed the corn-based diet performed better compared with those fed the tannin-free grain sorghum treatments. However, feeding certain grain sorghum varieties could result in similar feed efficiency to birds fed corn diets. Implications and Applications: This study demonstrates that tannin-free grain sorghum can be a feasible alternative to corn depending on the variety used, cost, and availability. It may also have implications to improve gut health upon further investigation of its mode of action. Overall, results may allow nutritionists in the commercial poultry industry to consider grain sorghum as an alternative to corn.