Níveis de sódio na alimentação de poedeiras comerciais leves no segundo ciclo de produção

Abstract

The objective of this study was to determine the ideal requirement of sodium to molted laying hens. The experimental period lasted 105 days, divided into five periods of 21 days. 150 Hisex White laying hens with 84 weeks-of-age were used. The experimental design was completely randomized in a factorial scheme (5x3) with treatments constituted by five levels of sodium (0.10, 0.15, 0.20, 0.25, and 0.30%) in the diets, and three postmolt stages (early = 21 days, medium = 63 days, and final = 105 days). The performance variables analyzed were: feed intake, egg production, feed conversion (kg / kg and kg / dz) and egg mass. The egg quality variables were: egg weight, yolk percentage, albumen and shell, yolk and albumen height, yolk color, specific gravity, Haugh Unit and breaking strength of the shell. Performance and egg quality results were evaluated by Tukey test at 1% and 5%. Eggshell resistance and weight gain results were evaluated by polynomial regression at 1% and 5%. Except the yolk height, all performance and egg quality variables were affected (p<0.05) by the sodium levels and the hens’ age postmolt. The level of 0.15% of sodium in diets to postmolt laying hens provided better performance and egg quality, especially in the eggshell. Higher levels of sodium negatively affected the performance and egg quality. Hens in the early stage of postmolt period presented better performance and egg quality. At long-term, the postmolt hens presented worst results.