University of Guilan Animal Production Research 2252-0872 6 4 2018 02 20 Effect of source and particle size of dietary fiber on performance and egg quality in commercial laying hens Effect of source and particle size of dietary fiber on performance and egg quality in commercial laying hens 93 106 2758 10.22124/ar.2018.8043.1235 FA P. Azizi Graduated MSc. Student, Department of Animal Science, Faculty of Agriculture and Natural Resources, Razi University, Kermanshah, Iran S. Moradi Assistant Professor, Department of Animal Science, Faculty of Agriculture and Natural Resources, Razi University, Kermanshah, Iran Journal Article 2017 07 19 This study was conducted to determine effect of sources and particle size of fiber on performance, egg quality and pH of excreta in laying hens. A total of 324 Lohmann LSL-lite laying hens was arranged in a factorial experiment with nine dietary treatments, each replicated six times. Experimental treatments consisted of two fiber sources (sunflower hulls, SFH and sugar beet pulp, SBP), two levels of fiber (2.5 and 5%), two fiber particle size (fine, 2 mm and coarse, 6 mm) with a control group. Results showed that main effects of sources, level and particle size of fibers did not significantly affect hen-day egg production, egg weight, egg mass, feed intake, feed conversion ratio and body weight gain. On week 30, inclusion of coarse SFH (5%) significantly reduced shell weight and shell thickness (<em>P</em>< 0.05), also yolk color was decreased in birds fed 2.5% of SFH with fine particle, whereas yolk color was greater in birds received 5% SBP than control (<em>P</em>< 0.0001). On week 38, main effect of fiber source was significant on haugh unit, and albumin quality was higher in SBP than SFH (<em>P</em>< 0.05). Feeding fiber sources elevated pH of excreta compared to control (<em>P</em>< 0.05). The inclusion of up to 5% SFH and SBP at the expense of the control diet did not have any negative effect on productive performance of laying hens, however, more attention is needed to effects on egg quality. This study was conducted to determine effect of sources and particle size of fiber on performance, egg quality and pH of excreta in laying hens. A total of 324 Lohmann LSL-lite laying hens was arranged in a factorial experiment with nine dietary treatments, each replicated six times. Experimental treatments consisted of two fiber sources (sunflower hulls, SFH and sugar beet pulp, SBP), two levels of fiber (2.5 and 5%), two fiber particle size (fine, 2 mm and coarse, 6 mm) with a control group. Results showed that main effects of sources, level and particle size of fibers did not significantly affect hen-day egg production, egg weight, egg mass, feed intake, feed conversion ratio and body weight gain. On week 30, inclusion of coarse SFH (5%) significantly reduced shell weight and shell thickness (<em>P</em>< 0.05), also yolk color was decreased in birds fed 2.5% of SFH with fine particle, whereas yolk color was greater in birds received 5% SBP than control (<em>P</em>< 0.0001). On week 38, main effect of fiber source was significant on haugh unit, and albumin quality was higher in SBP than SFH (<em>P</em>< 0.05). Feeding fiber sources elevated pH of excreta compared to control (<em>P</em>< 0.05). The inclusion of up to 5% SFH and SBP at the expense of the control diet did not have any negative effect on productive performance of laying hens, however, more attention is needed to effects on egg quality. https://ar.guilan.ac.ir/article_2758_8197d5f38cb10aafe2181b257fa9f11c.pdf