Sanders A M, Edwards H M, Rowland G N
Department of Poultry Science, University of Georgia, Athens 30602.
Br J Nutr. 1992 May;67(3):421-35. doi: 10.1079/bjn19920047.
The first experiment was a central composite rotatable design with calculated calcium levels of 6.2, 7.0, 9.0, 11.0, and 11.8 g/kg diet and total phosphorus levels of 5.2, 6.0, 8.0, 10.0, and 10.8 g/kg diet (2.8 g phytin-P/kg by analysis). This design involved three replicates for each rotatable point and fifteen replicates of the central point. The second experiment was a 4 x 4 factorial design with calculated Ca levels of 8.0, 10.0, 12.0, and 14.0 g/kg diet and calculated total P levels of 7.0, 9.0, 11.0, and 13.0 g/kg diet (2.5 g phytin-P/kg by analysis). There were four replicates for each treatment. In both 16 d experiments maize-soya-bean diets were used and each replicate consisted of one pen containing 10-d-old broad-breasted, white tom turkeys. The Ca and total P requirements for optimum growth were estimated to be 12.5 and 10.0 g/kg diet respectively. Bone ash was adequate at these levels of Ca and total P, but maximum bone ash was not achieved until much higher levels of Ca and total P were employed. At the required levels of Ca and total P for growth the incidences of Ca- and P-deficiency rickets were very low. There were no treatment effects on feed efficiency. Increasing dietary Ca decreased the incidence of the Ca-deficiency lesion. There was a quadratic response due to dietary total P on both P-deficiency rickets and plasma dialysable P; intermediate levels of dietary P resulted in low incidence of the P-deficiency lesion and high levels of plasma dialysable P. There was a strong negative correlation between the incidence of P-deficiency rickets and plasma dialysable P. Percentage retention was very low at high levels of dietary P and low levels of Ca which corresponded with slightly higher P-deficiency rickets and low plasma dialysable P. No such obvious relationships existed between Ca retention, incidence of Ca-deficiency rickets, and plasma Ca. The incidence of tibial dyschondroplasia was very low in the present study. There were pronounced dietary treatment effects on phytin-P retention; at 14 d percentage phytin-P retention treatment means ranged from 18 to 46 in Expt 1 and from 0 to 40 in Expt 2 with the highest retention of phytin-P at low levels at both Ca and total P.
第一个试验采用中心复合旋转设计，日粮中钙的计算水平为6.2、7.0、9.0、11.0和11.8 g/kg，总磷水平为5.2、6.0、8.0、10.0和10.8 g/kg日粮（经分析植酸磷为2.8 g/kg）。该设计每个旋转点设3个重复，中心点设15个重复。第二个试验为4×4析因设计，日粮中钙的计算水平为8.0、10.0、12.0和14.0 g/kg，总磷计算水平为7.0、9.0、11.0和13.0 g/kg日粮（经分析植酸磷为2.5 g/kg）。每个处理设4个重复。在这两个为期16天的试验中均使用玉米-大豆日粮，每个重复由一个饲养栏组成，栏内装有10日龄的宽胸白羽公火鸡。据估计，最佳生长所需的钙和总磷分别为12.5和10.0 g/kg日粮。在这些钙和总磷水平下骨灰含量充足，但直到采用更高的钙和总磷水平才达到最大骨灰含量。在生长所需的钙和总磷水平下，钙缺乏和磷缺乏佝偻病的发病率很低。各处理对饲料效率均无影响。增加日粮钙可降低钙缺乏病变的发生率。日粮总磷对磷缺乏佝偻病和血浆可透析磷均有二次响应；日粮磷处于中等水平时，磷缺乏病变的发生率较低，血浆可透析磷水平较高。磷缺乏佝偻病的发病率与血浆可透析磷之间存在很强的负相关。在高磷低钙日粮水平下，磷的保留率很低，这与稍高的磷缺乏佝偻病发病率和低血浆可透析磷相对应。钙的保留率、钙缺乏佝偻病的发病率和血浆钙之间不存在如此明显的关系。在本研究中，胫骨软骨发育不良的发病率很低。日粮处理对植酸磷的保留有显著影响；在试验1中，14天时植酸磷保留率处理平均值在18%至46%之间，试验2中在0%至40%之间，在钙和总磷水平均较低时植酸磷的保留率最高。
