Níveis de fibra na ração de recria (7 a 17 semanas de idade) e seus efeitos no crescimento e qualidade óssea de duas linhagens de poedeiras

Abstract

Our objective was to evaluate the effects of levels of neutral detergent fiber (14.5, 16.5, 18.5% NDF) in the growing ration (7ª to 17ª week of age) on bone quality of light and semi-heavy birds, this way 840 birds were distributed in a completely randomized with a factorial design 2 x 3 (two lines x three levels of NDF) with four replicates of 35 birds. During this phase, weekly, feed the birds were weighed, and at 17 weeks, two birds were selected per plot to be sacrificed and to remove thighs and drumsticks, which after remove the bones supplied femur and tibia for measuring length, weight, index Seedor, resistance and deformity. At the end of the growth phase the birds were transferred to the laying house, keeping the same experimental design, each plot consisted of 14 birds, totaling 336 birds. To evaluate the bone quality of laying hens, a bird was killed of per plot at 35 weeks of age, and adopted the procedures of the previous phase. As the data analysis no significant interaction between the factors NDF level and lineage for all variables at different stages. The NDF level of the diet did not significantly influence the growth, bones composition and quality in growing and laying phases. Regarding the effect of lineage, semi-heavy birds showed larger and heavier femurs and tibia, with higher Seedor index and lower deformity, ash and proteins than light birds. Howerver, resistance did not vary significantly among lineages. Light birds had better measures of shell quality. The rations used for feeding of pullets in the growing phase may contain up to 18.5% NDF without problems occur in development and bone quality of laying hens.