Starch digestibility and energy utilisation of maize- and wheat-based diets is superior to sorghum-based diets in broiler chickens offered diets supplemented with phytase and xylanase

Abstract

A study was conducted to compare maize, wheat and sorghum as the main feed grain in standard phytase and xylanase supplemented diets for broiler chickens. Six diets with different grain varieties (two wheat, two sorghum and two maize) were formulated in accordance with Ross 308 recommendations for starter, grower and finisher diets and were offered from 1 to 10, 11-26 and 27-35 days post-hatch, respectively. The six treatments were offered to 672 male Ross 308 chicks, with eight replicate cages per treatment and 14 birds per cage from 1 to 10 days post-hatch and 6 birds per cage from 11 to 35 days post-hatch. Over the 1-35 day experimental period, birds offered diets based on maize B generated the most efficient feed conversion ratio (FCR, 1.380), whereas birds offered red sorghum-based diets generated the poorest FCR (1.478). Likewise, in the finisher phase, birds offered both maize and wheat generated significantly greater apparent metabolisable energy (AME, MJ/kg DM), AME to gross energy ratio (AME:GE,MJ/MJ) and nitrogen corrected AME (AMEn, MJ/kg DM) than birds offered sorghum-based diets. Birds offered diets containing wheat A generated the greatest starch digestibility coefficient in the jejunum and ileum in both starter and finisher diets and red sorghum out performed white sorghum in terms of AME and starch digestibility. In the ileum, broiler chickens offered finisher diets based on wheat B had the highest protein digestibility. In conclusion, birds offered maize-based diets achieved the best growth performance and energy utilisation followed by birds offered wheat- and sorghum-based diets.