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Descripción
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| Lohmann Brown laying hens were used to study the influence of level (3.5 and 4.0%) and source (coded FIN, COA, and OYS) of Ca of the diet on productive performance and egg quality from 58 to 73 wk of age. The FIN diet contained 100% of the calcium carbonate as fine limestone (LIM) and in the COA and OYS diets, 40% of the fine LIM was substituted by either coarse LIM or oyster shell. Each treatment was replicated 8 times (24 hens caged in groups of 4). Productive performance and egg quality traits were recorded every 4 wk and tibiae characteristics and shell quality traits were determined at 73 wk of age. An increase in Ca from 3.5 to 4.0% improved egg production (71.2 vs. 74.9%; P ¡Ü 0.001), egg mass (49.0 vs. 51.4 g; P¡Ü 0.05), and feed conversion ratio (2.43 vs. 2.30 kg feed/kg egg; P ¡Ü 0.001). Also, an increase in Ca content improved the proportion of shell of the egg (9.98 vs. 10.20%; P ¡Ü 0.05), shell thickness (0.342 vs. 0.351 mm; P ¡Ü 0.01), and shell density (82.0 vs. 83.8 mg/cm2; P ¡Ü 0.001) but had no effect on other egg quality traits. Source of Ca had little effect on productive performance or on egg or shell quality. The only differences observed among treatments were for shell density that was lower for hens fed FIN than for hens fed COA with hens fed OYS being intermediate (81.9 vs. 84.0 vs. 82.7 mg/cm2; P ¡Ü 0.05). We conclude that brown hens in late phase of production require more than 3.5% Ca in the diet and that the substitution of 40% of fine LIM by coarse LIM or oyster shell does not affect productive performance and has little impact on shell quality and tibiae characteristics. | |
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Internacional
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Si |
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Nombre congreso
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97th Poultry Science Annual Meeting |
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Tipo de participación
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960 |
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Lugar del congreso
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Ni?¢gara Falls, Canad?¢ |
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Revisores
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Si |
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ISBN o ISSN
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1525-3171 |
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DOI
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Fecha inicio congreso
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20/07/2008 |
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Fecha fin congreso
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23/07/2008 |
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Desde la página
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90 |
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Hasta la página
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90 |
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Título de las actas
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Poultry Science 87 (1) |