High Dietary Calcium Causes Metabolic Alkalosis in Growing layers

摘要

One hundred and sixty healthy growers of 35 days of old were randomly divided into two groups. The growers in different groups were fed with normal calcium (Ca) (control, 8.5 g Ca/kg) diet and high calcium (HC, 36.3 g Ca/kg) diet respectively. The experiment lasted for 32 days. The clinical signs of growing layers were observed. Blood gas and electrolytes of serum and urine were determined. HC diet could cause watery diarrhea in growers. The growers raised on HC diet had significantly higher blood pH, HCO_3~-, BE and significantly lower blood PO_2, PCO_2, SO_2than that of the control. Phosphorus and potassium decreased, meanwhile, calcium increased in the HC group as compared with the control group. Sodium, magnesium and chlorine in serum had no significantly difference between the HC group and the control. Growers raised on HC diet had significantly higher urine pH than that of the control. For HC growers, urinary concentration and 24-h urinary excretion of calcium and chlorine was significantly higher, and magnesium, inorganic phosphorus and sodium were significantly lower than that of the control growers. It is concluded that some metabolic disorders associated with high dietary calcium in growing layers may be related to a state of metabolic alkalosis.