Effects of dietary copper sources on haematological, serum biochemical and hormonal profiles of laying hens.

A total of 224 pullets of 20 weeks of age were used to study the effects of two varying levels of dietary inorganic copper sources on the haematological, serum biochemical and hormonal performances of laying hens. They were assigned to two groups of experimental diets which were copper-free. Each group consists of four treatments. A group contains copper sulphate (CuSO4) supplement at 0, 100, 200 and 300 mg/kg diets while the other group contains copper Oxide (CuO) at the same inclusion rates. The pullets were randomly allotted to the eight (8) treatment diets and replicated seven (7) times with four (4) pullets per replicate in a 2 x 4 factorial arrangement. The experiment lasted for a period of sixteen weeks. At the end of the experiment, 3 birds/replicate were sacrificed; blood samples were collected for haematological, serum biochemical and hormonal studies. It was observed that copper oxide and copper sulphate significantly (P<0.05) enhanced the various performances of the laying hens in the parameters studied. However, CuSO4 at 100 and 200mg inclusion levels were observed to confer lower values in packed cell volume, haemoglobin and red blood cell count as compared with the control. Also, it was observed that blood viscosity significantly (P<0.05) increased as copper supplements increase in the diets. Furthermore, the result showed that there was significant difference (P<0.05) between treatments only for uric acid. However, significant differences (P<0.05) were observed at levels of inclusion for uric acid, glucose and cholesterol. [ABSTRACT FROM AUTHOR]