The Effect of Dietary Rye Inclusion and Xylanase Supplementation on Structural Organization of Bone Constitutive Phases in Laying Hens Fed a Wheat-Corn Diet

SIMPLE SUMMARY: Consumption of diets with a high-level incorporation of rye leads to an increase in the concentration of nonstarch polysaccharides, which cannot be utilized by poultry. The enzyme xylanase degrades arabinoxylans, the most common nonstarch polysaccharides present in both wheat and rye. In this study, the effect of dietary hybrid rye inclusion and enzyme xylanase supplementation to a diet of laying hens on bone quality was evaluated. Bone quality in laying hens is especially important as one of the bone functions is to store calcium and other minerals for eggshell production. The results of our study showed that modern hybrid rye varieties, when supplemented with exogenous xylanase, can be introduced to the diet of laying hens without any adverse effects on bone structure. ABSTRACT: This study was conducted to examine the effect of dietary rye inclusion and xylanase supplementation on the bone quality of ISA Brown laying hens. Ninety-six laying hens were assigned to four groups: fed with wheat–corn diet or rye–wheat–corn diet (25% of hybrid rye inclusion) or nonsupplemented or supplemented with xylanase (200 mg/kg of feed) for a period of 25 weeks, from the 26th to the 50th week of age. X-ray absorptiometry, X-ray diffraction, and Fourier-transform infrared spectroscopy were used to provide comprehensive information about the structural organization of bone constitutive phases of the tibia mid-diaphysis in hens from all treatment groups. Bone hydroxyapatite size was not affected by diet. Xylanase supplementation influenced the carbonate-to-phosphate ratio and crystallinity index in hens fed with both diets. Xylanase had more pronounced effects on bone mineral density and collagen maturity in hens fed with the rye–wheat–corn diet versus those fed with the wheat–corn diet. The results of this study showed that modern rye varieties, when supplemented with exogenous xylanase, can be introduced to the diet of laying hens without any adverse effects on bone structure.