Evaluation of hull-less barley genotypes varying in extract viscosity in broiler chick diets

Abstract

Both hull-less and hulled barley cultivars, representing high and low extremes in extract viscosity (reflective of soluble β-glucan content), were compared in broiler chick diets both with and without dietary β-glucanase supplementation. In both experiments both body weight gain ( P < 0.01) and feed conversion ( P < 0.01) of chicks fed barley were improved with β-glucanase. Body weight gain of chicks indicated a greater response to dietary β-glucanase in the high viscosity barleys (16.5%, Experiment 1; 23.5%, Experiment 2), although some response was also evident in chicks given low viscosity barley (5.6%, Experiment 1; 8.2%, Experiment 2). Feed conversions of chicks also indicated a larger response to β-glucanase supplementation for the high viscosity (−9.6%, Experiment 1; −15.0%, Experiment 2) as compared with low viscosity (−2.6%, Experiment 1; −7.4%, Experiment 2) barleys. Both high and low viscosity hull-less barley gave equivalent performance with β-glucanase supplementation. Comparisons with hulled barley indicated that hull-less barley diets gave higher body weight gain (8.2%, P < 0.01) and lower feed conversion (−3.83%, P < 0.10) in chick diets when supplemented with β-glucanase.