Influence of Various Dietary Factors on Bone Fragility of Caged Layers ,

Abstract

BONE fragility of caged layers often results in bone breakage during processing, causing down-grading of ready-to-cook hens. Many processors with batch-type pickers discriminate against or even refuse to buy caged layers. As the number of cage operations increases, bone fragility will become a more important economic factor to the poultry industry. As the hen lays, she depletes her skeletal system of calcium. Common (1938) showed that up to 24% of the total body calcium of hens laying on a low-calcium diet can be withdrawn from the skeleton for shell formation. Taylor and Moore (1954) reported that there was a reduction in percent shell immediately after pullets were placed on a low-calcium diet; the reduction became progressively greater with each egg laid. They also found that the percent bone ash of pullets dropped when they were placed on a low-calcium diet. Jones et al. (1965) reported that administration of dienestrol diacetate . . .