Xylanase supplementation improves the nutritive value of diets containing high levels of sorghum distillers' dried grains with solubles for broiler chickens

Background: An experiment was conducted to investigate the effect of sorghum distillers' dried grains with solubles (sDDGS) and xylanase supplementation in broiler chicken diets. A total of 432 Cobb-500 day-old male broiler chicks were used in a 4x2 factorial design (0, 100, 200 or 300 g kg⁻¹ sDDGS with or without xylanase supplementation). Each treatment was replicated six times with nine birds per replicate in a 35 day study. Results: Feed intake was increased (P<0.001) throughout the study with the inclusion of dietary sDDGS. Body weight gain (BWG) was unaffected except for the last 2 weeks of study, when birds that received 200 and 300 g kg⁻¹ sDDGS had higher (P<0.001) BWG. Feed conversion ratio (FCR) increased (P<0.05) as sDDGS in the diet rose to 100 g kg⁻¹ during the starter phase and the whole period of study. Over the starter period, xylanase supplementation improved (P<0.05) FCR, particularly for the highest inclusion of sDDGS. Protein digestibility deteriorated (P<0.001) as sDDGS in the diet rose to 300 g kg⁻¹. Xylanase reduced (P<0.001) the concentration of xylose in the ileum of birds. The activities of sucrase and maltase in the jejunal mucosa were reduced when birds were offered 200 and 300 g kg⁻¹ sDDGS. Incorporation of sDDGS increased (P<0.01) the total short-chain fatty acid concentration in the caeca. Conclusion: The results showed that diets containing large amounts of sDDGS will benefit from xylanase supplementation, particularly in terms of FCR.