Roland D A, Farmer M, Marple D
Poult Sci. 1985 Dec;64(12):2341-50. doi: 10.3382/ps.0642341.
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.
在实验1中，将海兰W36笼养母鸡饲喂钙含量分别为1.7%、2.9%、3.5%和4.1%的日粮，持续10周和16周。在实验2和4中，将迪卡布XL和海兰W36小母鸡饲喂钙含量分别为1.0%、1.7%和3.75%的日粮，为期3周（实验2）或直至每组25只小母鸡各产7枚蛋（实验4）。在实验3和5中，将迪卡布和海兰母鸡饲喂钙含量分别为1.5%（仅迪卡布）、1.75%、2.25%、2.75%和3.75%的日粮，持续8周。评判标准包括肝脏、脂肪垫、蛋和蛋壳重量、蛋的比重、产蛋量、采食量、肝脏脂肪和脂肪酸组成、肝脏出血评分以及体重。随着日粮中钙含量的降低，海兰鸡（实验1、4和5）的肝脏脂肪、体重（实验4除外）和采食量增加，但蛋的比重和蛋壳重量降低。日粮钙水平降低在实验1中对产蛋量没有影响，但在实验5中显著降低了产蛋量。随着日粮中钙含量的降低，肝脏出血评分显著增加（实验1）。随着日粮钙含量降低，迪卡布小母鸡（实验2）的采食量、脂肪垫重量和肝脏出血评分增加。肝脏脂肪没有增加。然而，在迪卡布母鸡（实验3）中，随着日粮钙含量降低，采食量和产蛋量显著下降。得出的结论是，给小母鸡或母鸡饲喂钙不足导致的过量采食对蛋大小或产蛋量没有有益影响，并且根据品种不同，会增加肝脏脂肪、肝脏出血评分、体重和脂肪垫重量。
