Calcium levels and calcium: available phosphorus ratios in diets for white egg layers from 42 to 58 weeks of age

Revista Brasileira de Zootecnia

Pastore, Silvana Marques¹  Rostagno, Horacio Santiago¹  Calderano, Arele Arlindo¹  Viana, Gabriel da Silva¹  Vellasco, Cássia Rampini¹  Almeida, Rodrigo Lopes de¹  Albino, Luiz Fernando Teixeira¹  Gomes, Paulo Cezar¹ 

[1]Universidade Federal de Viçosa, Brazil

关键词: birds;    mineral;    performance;    requirement    Introduction Over the years;    commercial layer strains have been genetically improved in order to be more productive;   

DOI  :  10.1590/S1516-35982012001200007

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

The experiment was conducted to determine the nutritional requirement of calcium and the best calcium:available phosphorus ratio for commercial layers at the post-laying peak. A total of 324 Hy-Line W-36 laying hens were utilized in the period from 42 to 58 weeks of age, distributed in a completely randomized design in a 3 × 3 factorial arrangement, composed of three levels of calcium (39, 42 and 45 g/kg) and three calcium:phosphorus ratios (12.12:1; 10.53:1; and 9.30:1), totaling nine treatments with six replications and six birds per experimental unit. There was no significant effect from the calcium levels × calcium:phosphorus ratio interaction for any of the variables studied. The calcium levels and the calcium:phosphorus ratios did not affect the variables performance or egg and bone quality. At the evaluation of the calcium:phosphorus balance, as the levels of calcium of the diet were raised, the intake of calcium and phosphorus and the contents of mineral matter and calcium in the excreta increased linearly, and the retention of calcium by birds decreased linearly. With the reduction of the calcium:phosphorus ratios of the diet, intake, retention and excretion of phosphorus by layers increased. Diets containing calcium at 39 g/kg and a calcium:phosphorus ratio of 12.12:1, corresponding to an increase in calcium of 3.51 g/bird/day and available phosphorus of 289 mg/bird/day, meet the requirements of calcium and available phosphorus of white egg layers in the period from 42 to 58 weeks of age.

【 授权许可】

CC BY-NC