Hull-less barley contains approximately 13% less fiber than hulled barley. This increases the concentration of protein, energy and beta-glucan. The beta-glucan level of the diet may result in increased digesta viscosity and reduced retention of nutrients. The impact of beta-glucan in diets can be alleviated by enzyme supplementation. Therefore, the objective of this study is to evaluate the impact of beta-glucan and/ or phytase enzyme in hull-less barley based diets supplemented with either 3 or 6% canola oil or tallow when fed to ISA - brown- or ISA white-shell layers from 18 to 34 wk of age. The two strains (n=480/strain) were randomly assigned to five replicate groups of six hens fed 16 diets (2 fat sources (canola oil vs. tallow) ×2 fat levels (3 vs. 6 % of total diet) × 4 enzyme treatments (no enzyme, beta-glucanase (Avizyme 1100), phytase (Natuphos) and beta-glucanase and phytase) ad-libitum from 18 to 34 wk of age. Hull-less barley was pre-pelleted to destroy endogenous enzyme activity, and then incorporated into mash diets. The ISA brown shell layers had higher egg mass yield than ISA white-shell layers. Hull-les barley based dies supplemented with tallow as compared to canola oil had higher egg mass yield. Egg mass yield was not improved with enzyme supplementation.
