Effect of the levels of calcium and particle size of limestone on laying hens

Revista Brasileira de Zootecnia

José Anchieta De Araujo²  José Humberto Vilar Da Silva¹  Fernando Guilherme Perazzo Costa¹  Janaína Maria Batista De Sousa¹  Patrícia Emília Naves Givisiez¹  Nilva Kazue Sakomura¹ 

[1] ,UFPB CCA

关键词: bone strength;    egg quality;    performance;    desempenho;    qualidade dos ovos;    resistência óssea;   

DOI  :  10.1590/S1516-35982011000500009

来源: SciELO

【 摘 要 】

This experiment was conducted to evaluate the effect of levels of calcium (Ca) and particle size of limestone (LS) for laying hens. It was used 216 Dekalb White laying hens at 25 to 49 weeks of age in a completely randomized design in a 3 × 2 factorial arrangement, composed of three levels of calcium (3.92, 4.02 and 4.12%) and two particle sizes of limestone (thin - 0.60 mm; and thick - 1.00 mm), resulting in 6 treatments with six replicates of six birds. There was no significant effect of levels of calcium and limestone particle size neither of the interaction calcium × particle size for feed intake, egg weight, specific gravity, shell thickness, shell percentage, Haugh unit, calcium and phosphorus digestibility and percentage of digestive tract. Production, mass, conversion by mass and conversion by egg dozen had their best results with 4.12% of calcium in the diet. Percentage of gizzard and feed intake observed at 3:00 p.m. improved as limestone granulometry improved from 0.60 to 1.00 mm. There was an interaction effect among calcium level and limestone granulometry for breaking strength of tibia, bone density, length of the small intestine and feed intake at 6:00 a.m.; 9:00 a.m., 12:00 p.m., 6:00 p.m. and 9:00 p.m., respectively. It is recommended the addition of 4.12% of calcium and limestone in the thick granulometry (1.00 mm) for a better performance of commercial laying hens. More studies are needed to elucidate the mechanisms involved in the alteration of nutritional behavior of laying hens in response to changes in the levels of calcium and in the granulometry of limestone in the rations.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License