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The effects of dietary intake and of dietary concentration of copper sulphate on the laying domestic fowl: Effects on laying performance and tissue mineral contents |
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| Authors: | Mary H. Stevenson J. Pearce N. Jackson |
| Affiliation: | 1. Department of Agricultural and Food Chemistry , The Queen's University of Belfast , Newforge Lane, Belfast , BT9 5PX , Northern Ireland;2. Department of Agriculture , Northern Ireland |
| Abstract: | 1. Sixty white hybrid (Shaver 288) laying hens were subjected to three main dietary regimens for 5 d: ad libitum feeding of control and CuSO4‐supplemented diets, force‐feeding these same diets to the same intake as that of the ad libitum control diet and pair‐feeding the control CuSO4‐free diet to intakes equivalent to those of supplemented diets. 2. Final body weight of the force‐fed birds was significantly greater than of the other groups. Egg number and weight were significantly reduced as food intake decreased. 3. Liver weight per unit body weight was significantly increased and oviduct and ovary weights/kg body weight were significantly reduced by force‐feeding. As food intake decreased kidney and gizzard weights per unit body weight were significantly increased. 4. The concentrations and total contents of Cu and Zn in liver were significantly increased in the ad libitum and force‐fed groups. 5. Force‐feeding CuSO4‐supplemented diets, which eliminated difference in food intake, confirmed that CuSO4 per se affected tissue weights and mineral concentrations as distinct from effects due to the reduced food intake associated with increasing dietary CuSO4. |
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