Calcium Intake Level as Factor of Influencing of the Eggshell Qualities in Laying Hens
Abstract
The experiments were carried out on four groups of Hy-Line var. Brown hens (n = 350 each) monitored from 20 to 68 weeks of age. The hens were fed on diets which provided the following calcium intakes (%): 2.56 and 3.12 in groups I and II, respectively, 3.86 in control and 4.22 in group III. The shell weight increased during the laying period proportionally to the ingested calcium. The thickness of the eggshell decreased: the decrease was higher in the groups which ingested less calcium. The eggshell strength increased from 20 to 36 weeks of age in all the hen groups. Further, the eggshell strength decreased from 36 to 68 weeks of age. These decreases were higher as the amount of calcium intake increased. In conclusion, calcium diet influences on eggshell properties are age-dependent and more pronounced at the peak of laying period. The increase in diet calcium content from 3.86 to 4.22% has less and negative influences on the physical properties of the eggshell.
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