日粮硫、镁水平对肉鸡血液酸碱平衡和胫骨软骨发育不良的影响

Effects of Different Levels of Dietary Sulphur and Magnesium on Acid-Base Balance of Blood and Incidence of Tibial Dyschondroplasia in Broiler Chicks

在玉米豆粕日粮中，添加３ 个水平的Ｍｇ０ 和（ＮＨ４）２ＳＯ４ ，使日粮中的硫、镁水平分别达到０ ．４０ ％ 、０ ．６５ ％ 、０ ．９０ ％ 和０ ．１７ ％ 、０ ．３７ ％ 、０ ．５７ ％ ，组成９ 个处理日粮，饲喂４０５ 只艾维茵肉用公雏，研究日粮电解质平衡对２１ 日龄肉鸡生长性能、胫骨软骨发育不良（ＴＤ） 发生、血液酸碱平衡的影响。在一定范围内日粮高硫具有诱食作用。日粮高镁同时降低了采食量、日增重和饲料效率（Ｐ＜ ０ ．０５） 。日粮高硫明显降低了ＴＤ 发生率和生长板厚度（Ｐ＜ ０ ．０５） ，高镁则起到相反的作用。日粮电解质平衡与肉鸡ＴＤ 发生率呈线性负相关（Ｒ＝ － ０ ．８２５） 。虽然日粮镁、硫水平对血液ｐＨ 影响不显著，但日粮高硫降低了碱超和碱贮（Ｐ＜ ０ ．０５） ，酸化了血液；日粮高镁则增加了碱超（Ｐ＜ ０ ．０５） ，起到了碱化作用。试验结果表明，由日粮硫、镁水平调节的电解质平衡可能通过改变血液酸碱平衡，成为影响肉鸡胫骨软骨发育的重要因素。

one-day-old male Avian broiler chicks, divided into nine groups with three replicates per group,were fed ad libitum corn-soybean diet with the addition of 0.40%,0.65%,0.90% sulphur as (NH 4)SO 4 and 0.17%,0.37%, 0.57%, magnesium as MgO to determine the influence of dietary electrolyte balance on acid-base of blood and incidence of tibial dyschondroplasia. Addition of sulphur increased feed intake, body gain and incidence of TD in 21-day-old brroiler chicks. All above indexes and feed conversion efficiency were decreasing the increasing magnesium levels. Dietary electrolyte balance was remarkabely correlated to incidence of TD(R=-0.825).The acidification of the blood due to the addition of sulphur was balanced by a decrease in the base excess and HCO 3 -.Addition of magnesium alkalized the bolld in the same way. These results suggested that dietary electrolyte balance could affect the incidence of TD by changing acid-base balance of blood.