Apparent metabolizable energy and performance of broilers fed selected grain sorghum varieties

Abstract

Objective: The objective of this study was to determine the nitrogen-corrected apparent ME (AMEn) content of tannin-free red/bronze, white/tan, and US No. 2 varieties of grain sorghum fed to commercial broilers and evaluate its effects on growth performance as an alternative to corn in poultry diets. Materials and Methods: Nitrogen-corrected apparent ME content of red/bronze, white/tan, and US No. 2 grain sorghum varieties was determined using a dextrose control diet as the standard fed to 112 mixed-sex Cobb 500 female × Hubbard male broilers. Weekly measures of mean BW and feed consumption were used to calculate BW gain, feed intake, and feed conversion ratio. Analyses were based on a 2 × 4 factorial arrangement of treatments with age (grower and finisher phases) and grain types (corn-dextrose, red/bronze, white/tan, and US No. 2) defining the treatments. Cage was the experimental unit with data analyzed using JMP Pro version 15.2.0 (SAS Institute Inc.). Results and Discussion: Mean AMEn values of modern grain sorghum varieties for broilers in the grower diet phase were determined as 3,336 (red/bronze), 4,000 (white/tan), and 3,341 (US No. 2) kcal/kg and, in the finisher-diet phase, as 3,001 (red/bronze), 3,599 (white/tan), and 3,599 (US No. 2) kcal/kg (P = 0.0155). No significant differences among treatments for growth performance (BW gain, feed intake, feed conversion ratio) in the grower- and finisher-diet phases were observed. Implications and Applications: Responses indicate the potential for grain sorghum to replace corn without suboptimal effects on broilers. Growth performance trials with the full substitution of corn in feed formulation will be necessary to validate AMEn values and evaluate additional performance parameters.