Effects of Dietary Inclusion of Guar Meal Supplemented by β-Mannanase on Performance of Laying Hens, Egg Quality Characteristics and Diacritical Counts of White Blood Cells

Abstract

Problem statement: Using Guar Meal (GM) in poultry diets has being limited because of having β-mannan, one of the Nonstarch Polysaccharides (NSP). In this study we try evaluating effects of enzyme supplementation of GM-included diets on productive performance of laying hens. Approach: A total number of 144 Lohmann LSL-Lite hens were divided in 24 cages (n = 6). Based on a 3 × 2 factorial arrangement of treatments, six iso-caloric and iso-nitrogenous diets including 3 levels of GM (0.0, 35.0 and 70.0 g kg⁻¹) with and without enzyme (Hemicell® a β-mannanase-based enzyme, 0.0 and 0.6 g kg⁻¹) were assigned to hens in 4 cages (replicates). Data was analyzed based on completely randomized design using GLM procedure of SAS. Results: Dietary GM inclusion significantly affected on Egg Production (EP) on weeks 2, 4 and 6 as well as the overall trail period. Hens fed the GM-included diets did have decreased EP compared to hens fed the control diet. Almost the same trend was observed in terms of Egg Mass (EM); so that hens fed the GM-included diets showed decreased EM compared to the hens fed the control diet. Enzyme supplementation did not have significant effect on EP in the present experiment, but EM was significantly improved in the hens fed the β-mannanase-supplemented diets on weeks 3, 6 and the overall experimental period. Dietary inclusion GM increased Feed Conversion Ratio (FCR) of laying hens compared to the hens fed the control diets on weeks 2, 4, 6 and overall trial period. Conclusion/Recommendations: Including GM in laying hens’ diets more than 3% may decrease productive performance. Supplementing corn-soybean or corn-soybean-GM diets by β-mannanase would have beneficial effects on performance of hens especially in terms of FCR and EP.