Calcium and its relationship to excess feed consumption, body weight, egg size, fat deposition, shell quality, and fatty liver hemorrhagic syndrome.

In Experiment 1, Hyline W36 caged hens were fed diets containing 1.7, 2.9, 3.5, and 4.1% calcium for 10 and 16 weeks. In Experiments 2 and 4, Dekalb XL and Hyline W36 pullets were fed diets containing 1.0, 1.7, and 3.75% calcium for 3 weeks (Exp. 2) or until 25 pullets from each group laid 7 eggs (Exp. 4). In Experiment 3 and 5, Dekalb and Hyline hens were fed diets containing 1.5 (Dekalb only), 1.75, 2.25, 2.75, and 3.75% calcium for 8 weeks. Criteria were liver, fat pad, egg and shell weights, egg specific gravity, production, feed consumption, liver fat and fatty acid composition, liver hemorrhage score, and body weight. As percent dietary calcium decreased, Hyline birds (Exp. 1, 4, and 5) had increased liver fat, body weight (except Exp. 4), and feed consumption, but egg specific gravity and shell weight decreased. Reduced dietary calcium levels had no effect on egg production in Experiment 1 but significantly reduced production in Experiment 5. Liver hemorrhage score significantly increased as percent dietary calcium decreased (Exp. 1). As dietary calcium decreased, Dekalb pullets (Exp. 2) had increased feed consumption, fat pad weight, and liver hemorrhage score. There was no increase in liver fat. However, in Dekalb hens (Exp. 3), feed consumption and egg production were significantly decreased as dietary calcium decreased. It is concluded that overconsumption caused by feeding pullets or hens inadequate calcium had no beneficial effect on egg size or egg production and, depending on strain, increased liver fat, liver hemorrhage score, body weight, and fat pad weight.