EVALUATION OF HULL-LESS BARLEY GENOTYPES VARYING IN EXTRACT VISCOSITY IN BROILER CHICK DIETS

Both hull-less and hulled barley cultivars, representing high and low extremes in extract viscosity (reflective of soluble beta-glucan content), were compared in broiler chick diets both with and without dietary beta-glucanase supplementation. In both experiments both body weight pin (P < 0.01) and feed conversion (P < 0.01) of chicks fed barley were improved with beta-glucanase. Body weight gain of chicks indicated a greater response to dietary beta-glucanase in the high viscosity barleys ( 1 6.5%, 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 beta-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 beta-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 beta-glucanase.