Effects of dietary barley level on the performance of Leghorn hens

Abstract

Three experiments were carried out to examine the effects of dietary barley level on the performance of Leghorn hens. A 4 × 2 factorial arrangement of treatments was used in exps. 1 and 2 where there were four dietary barley levels (0, 15, 30 or 60%) and two commercial genotypes of hens. Experiment 3 contained a 3 × 2 × 2 arrangement of treatments involving three dietary barley levels (15, 30 or 60%), two cultivars of barley (2- or 6-row) and two levels of β-glucanase supplementation (0 and 0.1% of the diet). Egg production, feed intake, mortality, egg grades, body weight, and eggshell and interior quality data were collected from 140 to 490 d of age. The data from exps. 1 and 2 were combined for statistical analysis. There was a linear relationship (P < 0.001) between dietary barley level and feed conversion in exps. 1 and 2. Differences (P ≤ 0.05) were observed between the two genotypes for 140- and 490-d body weights, age at 50% egg production, hen housed egg numbers, feed conversion and monetary returns. Dietary barley level, in exp. 3, had a quadratic effect (P ≤ 0.05) on egg production (both HD % and HH no.) and monetary returns and a linear effect (P < 0.01) on feed conversion. Source of barley and dietary β-glucanase supplementation had little effect on performance. Diets for Leghorn hens may contain up to 60% barley, but optimum production performance occurred at a lower level. Key words: Barley, hens, β-glucanase, barley cultivar