An experiment was conducted to test the hypothesis that pharmacological
levels of dietary copper could reduce egg cholesterol content. Local Mamourah strain
hens 36 weeks of age were fed corn and soybean meal diets with 0, 500, 750 and
1000 mg/kg diet as copper sulphate (CUS04. 5 HzO) and copper chloride (CuClz. 2
HzO). At the end of experimental periods (28 and 56 days, respectively) three eggs
per group were randomly taken to determine yolk cholesterol and total lipids. Results obtained were as follows: A significant (P<0.05) decrease in blood hemoglobin value (Hb) was observed at
500 mg/kg diet of copper source during the two experimental periods. Hb value
was not affected by changing the dietary Cu source. A negative decrease in Cu plasma concentration was observed for different levels
and sources of copper. Increasing dietary copper from zero to 1000 mg/kg diet the amount of cholesterol
in plasma and yolk decreased linearly (P<0.05) and numerically. Levels at 750
and 1000 mg/kg diet decreased the plasma and yolk cholesterol by about 7.52,
19.40,20.62 and 30.92%, respectively, during 8 weeks of experimental period.
Copper supplementation positively affected plasma total lipids. Yolk lipids could be lowered substantially (15.78%) by the addition of 1000 mg/kg
diet when compared with control group. Liver weight per unit body weight was depressed for 500 and 750 mg Ikg diet of
copper source. Cu concentration in the liver increased for all dietary levels. These results suggested feed pharmacological levels and sources of copper to
laying hens will produce some physiological responses depending on the strain type
and duration of feeding.