Keshavarz K
Department of Animal Science, Cornell University, Ithaca, New York 14853, USA.
Poult Sci. 1996 Oct;75(10):1227-35. doi: 10.3382/ps.0751227.
Three experiments were conducted to determine whether shell quality, bone mineralization, and other production traits could be improved by adding vitamin C (ascorbic acid) to laying hen diets. The period of each experiment was 12 wk. Experiment 1 consisted of a 2 x 2 x 3 factorial design with two levels of Ca (2.8 and 3.8%), two levels of cholecalciferol (vitamin D3; 2,200 and 4,400 IU/kg diet), and three levels of vitamin C (0, 125, and 250 ppm). Experiment 2 consisted of a 2 x 3 x 2 factorial design with two levels of Ca (2.8 and 3.8%), three levels of vitamin D3 (250, 500, and 2,000 IU/kg diet), and two levels of vitamin C (0 and 250 ppm). Experiment 3 consisted of a 2 x 4 factorial design with two sources of vitamin D3 (12.5 micrograms vitamin D3/kg diet or 12.5 micrograms 25-OH-D3/kg diet) and four levels of vitamin C (0, 250, 500, and 1,000 ppm). Calcium level was kept constant at 3.5% for all the diets in Experiment 3. Production performance was not influenced by dietary treatments in Experiment 1. In Experiment 2, feed conversion was improved (P < 0.05) due to increasing the dietary Ca, and egg weight and egg size were increased (P < 0.05) due to adding 250 ppm vitamin C to the diet. In experiment 3, albumen quality was increased by the addition of 1,000 ppm vitamin C to the diet. Egg specific gravity was increased in Experiments 1 and 2 only, due to increasing the Ca level (P < 0.05). In Experiment 2, increasing the Ca level and increasing the vitamin D3 level from 250 to 2,000 ppm reduced (P < 0.05) the number of cracked eggs, but incidence of cracked eggs was increased with the addition of 250 ppm vitamin C to the diet. In Experiment 1, plasma level of 1,25(OH)2D3 was greater (P < 0.05) for hens fed 2.8 than 3.8% Ca, but blood acidbase balance was not influenced by dietary regimens. Bone ash was not influenced by dietary treatments in any of the experiments. The data indicated that a supplemental level of vitamin C had no beneficial effects on shell quality and bone mineralization under the conditions of the current experiments.
进行了三项试验，以确定在蛋鸡日粮中添加维生素C（抗坏血酸）是否能改善蛋壳质量、骨矿化及其他生产性能指标。每项试验为期12周。试验1采用2×2×3析因设计，有两个钙水平（2.8%和3.8%）、两个胆钙化醇（维生素D3；2200和4400 IU/kg日粮）水平以及三个维生素C水平（0、125和250 ppm）。试验2采用2×3×2析因设计，有两个钙水平（2.8%和3.8%）、三个维生素D3水平（250、500和2000 IU/kg日粮）以及两个维生素C水平（0和250 ppm）。试验3采用2×4析因设计，有两种维生素D3来源（12.5微克维生素D3/kg日粮或12.5微克25-羟基-D3/kg日粮）以及四个维生素C水平（0、250、500和1000 ppm）。试验3中所有日粮的钙水平保持在3.5%不变。试验1中生产性能不受日粮处理的影响。试验2中，由于日粮钙水平增加，饲料转化率得到改善（P<0.05），且由于日粮中添加250 ppm维生素C，蛋重和蛋尺寸增加（P<0.05）。试验3中，日粮添加1000 ppm维生素C可提高蛋白质量。仅在试验1和试验2中，由于钙水平增加，蛋比重增加（P<0.05）。试验2中，钙水平增加以及维生素D3水平从250 ppm提高到2000 ppm可减少（P<0.05）破蛋数量，但日粮中添加250 ppm维生素C会增加破蛋发生率。试验1中，饲喂2.8%钙的母鸡血浆1,25(OH)2D3水平高于（P<0.05）饲喂3.8%钙的母鸡，但日粮处理对血液酸碱平衡无影响。在任何一项试验中，日粮处理均不影响骨灰含量。数据表明，在当前试验条件下，补充维生素C对蛋壳质量和骨矿化无有益影响。
