Balnave D, Zhang D
Department of Animal Science, University of Sydney, Camden, New South Wales, Australia.
Poult Sci. 1993 Mar;72(3):603-6. doi: 10.3382/ps.0720603.
Production variables, eggshell defects, eggshell quality, the concentration of calcium-binding protein (CaBP), and the activity of carbonic anhydrase (CA) in the shell gland mucosa were determined in hens receiving town water (10 mg Na/L), or town water supplemented with 2 g NaCl/L (796 mg Na/L). Five treatments were examined. Control hens received town water and a proprietary layer mash containing .17% Na. The remaining four treatments received the water containing NaCl (2 g/L). Hens of Treatment 2 were fed the proprietary layer mash and those of Treatments 3, 4, and 5 received, respectively, the layer mash containing supplements of Zn-methionine (Zinpro-200; .5 g/kg), Zn sulfate (ZnSO4.7H2O; .46 g/kg), or chelated Zn-EDTA (.54 g/kg) to supply the same concentration of Zn (.1 g/kg). The treatments were applied for 6 wk. Hens receiving the saline drinking water without any dietary Zn supplement produced significantly (P < .05) more eggs with shell defects than hens receiving the town water. This increase in the incidence of eggshell defects was associated with significant reductions in eggshell breaking strength, the concentration of CaBP, and the activity of CA. Supplementing the saline drinking water with any of the three Zn compounds significantly reduced the incidence of eggshell defects and in some cases improved shell breaking strength, the concentration of CaBP, and the activity of CA.
对饮用城镇水（10毫克钠/升）或添加2克氯化钠/升（796毫克钠/升）的城镇水的母鸡，测定了生产变量、蛋壳缺陷、蛋壳质量、壳腺黏膜中钙结合蛋白（CaBP）的浓度以及碳酸酐酶（CA）的活性。共检查了五种处理方式。对照母鸡饮用城镇水并饲喂含0.17%钠的专用蛋鸡配合饲料。其余四种处理方式的母鸡饮用含氯化钠的水（2克/升）。处理2组的母鸡饲喂专用蛋鸡配合饲料，处理3、4和5组的母鸡分别饲喂添加了蛋氨酸锌（Zinpro - 200；0.5克/千克）、硫酸锌（ZnSO₄·7H₂O；0.46克/千克）或螯合锌 - EDTA（0.54克/千克）的蛋鸡配合饲料，以提供相同浓度的锌（0.1克/千克）。这些处理方式持续应用6周。饮用无任何日粮锌补充剂的盐水的母鸡所产有蛋壳缺陷的蛋显著（P < 0.05）多于饮用城镇水的母鸡。蛋壳缺陷发生率的这种增加与蛋壳抗破碎强度、CaBP浓度和CA活性的显著降低有关。用三种锌化合物中的任何一种补充盐水显著降低了蛋壳缺陷的发生率，在某些情况下还提高了蛋壳抗破碎强度、CaBP浓度和CA活性。
