Limestone particle sizes and lighting regimens on egg and bone quality of laying hens

作者：de Souza Xavier Regina Patricia; Freitas Ednardo Rodrigues; Braz Nadia Melo; Pereira Farias Nadja Naiara; Lima Raffaella Castro; Watanabe Pedro Henrique; Jeronimo Nascimento Germano Augusto; Mendes Peixoto Maria Simone

来源：Pesquisa Agropecuaria Brasileira, 2015, 50(8): 718-725.

DOI：10.1590/S0100-204X2015000800010

• egg mass
• shell thickness
• specific gravity
• tibia

The objective of this work was to evaluate the effect of limestone particle sizes in the diet and of lighting regimes on the egg and bone quality and on the performance of commercial laying hens. Three hundred Hissex White layers, at 18 weeks of age, were distributed in a completely randomized design, in a 5x2 factorial arrangement (coarse limestone in the diet at 0, 25, 50, 75, and 100%; with or without artificial light), with five replicates of six birds. No significant interaction was observed between particle sizes and lighting regime for the evaluated parameters. There was no significant effect of coarse limestone level in the diet on the performance and egg quality of hens; however, bone deformity (3.23 to 4.01 mm), strength (5.19 to 6.70 kgf cm(-2)), and mineral matter (51.09 to 59.61%) improved as the proportion of coarse limestone increased. For lighting regime, the treatment with artificial light yielded higher Haugh unit values (87.17 vs. 85.54) than that with natural light only. Greater limestone particles improve bone quality of laying hens, and the use of artificial light can benefit the albumen quality of the eggs.

• 出版日期2015-8