SciELO - Scientific Electronic Library Online

vol.38 issue3Digestible lysine requirements of laying hens from 54 to 70 weeks of ageBiological availability and calcium requirements of growing equines receiving diets with different calcium levels author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Revista Brasileira de Zootecnia

On-line version ISSN 1806-9290


FERNANDES, Jovanir Inês Müller et al. Effect of vitamin K on bone integrity and eggshell quality of white hen at the final phase of the laying cycle. R. Bras. Zootec. [online]. 2009, vol.38, n.3, pp.488-492. ISSN 1806-9290.

The effect of four levels of dietary vitamin K (vit. K) on production, egg quality and bone structure of laying hens near the end of the production cycle were studied. A total of 192 Hy-Line, W-36 hens, 67 weeks of age, were distributed into a completely randomized design with four treatments (0, 2, 8, 32 mg vit. K/kg of diet), six replicates and eight birds per experimental unit. Corn-soybean-meal basal diets were isonitrogenous (15.5% crude protein), isoenergetic (2,790 kcal ME/kg), isocalcium (4.25% Ca) and isophosphorus (0.40% available P). Vitamin K supplementation did not alter egg mass, feed intake, feed conversion (kg/kg), bone breaking strength, specific egg gravity, eggshell weight, thickness and percentage of thin and cracked shell. A linear effect on egg weight, laying percent, and feed conversion (kg/dozen) was observed, as well as a quadratic effect on the ash bone content. In conclusion, the inclusion of increasing levels of vitamin K to the diet influenced performance and bone mineralization, but not eggshell quality. The lack of consistency in the efficiency of supplemental vitamin K on eggshell quality may be due to the age of hens.

Keywords : eggshell quality; layer; osteoporosis.

        · abstract in Portuguese     · text in English     · English ( pdf epdf )


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