高钙日粮致鸡尿液及尿沉渣变化的研究

100羽伊沙雏蛋鸡饲养至35日龄，随机均分为对照组和高钙日粮组。对照组饲喂全价雏蛋鸡料(含钙1．0％)，高钙组在此基础上添加石粉使实际含钙量达3．85％。对两组鸡均进行结肠造口术，收集尿液，研究鸡尿液及尿沉渣的变化。结果表明，高钙日粮导致严重的肾脏病变和病理组织学损害，造成轻度痛风；病鸡尿量显增加，尿液密度降低，pH值升高；高钙组鸡尿液中尿酸、钙、钾、钠与镁的相对含量均低于对照组，无机磷的相对含量与对照组相似；高钙组鸡24h尿液中尿酸、钙、镁及无机磷的总量显高于对照组，钾和钠的总量低于对照组。扫描电镜下可见高钙组尿沉渣晶体结构发生变化，以针状较多。能谱分析表明，高钙组尿沉渣中钙、磷含量升高，而钾、钠含量均下降。

Effects of high dietary calcium on the urine and urinary deposit in pullets

One hundred pullets of 5 days old were selected for the experiment.At 35 days of age,the pullets were randomly divided into control and experimental groups.The control group was fed with normal dietary and the experimental group was fed with a high calcium(3 85%)in dietary.Pullets in both groups were colostomized to collect the urine,quantifying effects of high dietary calcium on urine and urinary deposit composition.The results showed that excessive dietary calcium during the pullet growing phase could cause severe damage of kidney.Pullets raised on high dietary calcium had significantly higher urine pH and larger volume of urine than that of the control.The high dietary calcium significantly increased the total content of uric acid,calcium,magnesium,inorganic phosphorous in urine and decreased the sodium,potassium in urine.Scanning electron microscope of urinary deposit showed that high calcium can change the crystal structure.X ray energy dispersive spectrometer revealed that calcium,phosphorus increased and sodium,potassium decreased in the urinary deposit in the experimental group as compared with the control group.