Effects of withdrawal of copper sulphate from the diet of the mature domestic fowl with special reference to production and tissue mineral content

Abstract

I . Cereal-based diets containing 0, 500, 1000 or zoo0 mg added copper/kg were offered ad lib. t o laying hens for 8 weeks. All the hens were subsequently offered the control diet (no added Cu, 7.5 mg Cu/kg).2. Hens from each treatment were killed at 0, 2 , 4, 6 and 8 weeks after removal of the Cu-supplemented diets. Records were kept of body-weight, food consumption and egg production. 3. After slaughter, blood haemoglobin, packed cell volume, serum Cu and aspartate aminotransferase (AAT; EC 2.6. I . I ) were assayed. The liver, kidneys, oviduct, ovary, gizzard, caeca and bile duct were weighed.4. Mean Cu, zinc and iron concentration of liver, kidneys and caecal contents were determined. 5. The adverse effects of Cu on body-weight, food intake, egg production and liver, oviduct, ovary, gizzard and bile weights were rapidly reversed by removal of added Cu from the diets.6. Greatly enhanced liver Cu concentration resulted from feeding the high-Cu diets but this effect was rapidly reversed on removal of added Cu from the diets. Liver Fe concentration showed a less marked but similar effect.7. The Cu concentration of caecal contents was increased by Cu supplementation and rapidly reduced after withdrawal of the Cu-containing diets.

An attempt to distinguish between the direct and indirect effects, in the laying domestic fowl, of added dietary copper sulphate

“…The increase in kidney Cu concentration with decreasing food intake is similar to the effect found by Stevenson & Jackson (1980b) and is obviously attributable to the presence of the CuSO, rather than level of food intake. Stevenson & Jackson (19806) suggested that an increase in kidney Fe concentration was related to increasing dietary CuSO, but the present results indicate that this effect is an indirect one due to decreased food intake and not directly due to dietary CuSO, concentration.…”

“…The slight but statistically significant increase in liver Zn per unit dry weight with reduced food intake appears to be a concentration effect resulting from reduced liver weight since the total Zn content decreased. An increase of liver Zn concentration in the presence of added dietary CuSO, has been reported by Stevenson & Jackson (1980b). This increase of the liver Zn in the presence of added dietary Cu has also been noted in the pig by Ritchie et al (1963) and Suttle & Mills (1966) and does not necessarily indicate a lack of antagonism at the level of the intestine or other tissues since such an antagonist effect has been found by these authors.…”

Effect of Dietary Supplementation With Chelated Copper Methionine on Some Chemical Metabolites and Ovarian Activity of Doe Rabbit and Their Litter Performance

“…Indeed, serum copper concentrations at the same two periods showed the same pattern, which means a direct effect of copper on the ovarian activity. The same observation noted by Jackson, (1980 and1981) who studied the direct and indirect effects of added dietary copper sulphate in laying domestic fowl and concluded that there was evidence of a direct effect of copper sulphate on egg production and possible on oviduct and ovary weight. Also, Kendall et al (2003) confirmed the same observation by studying the expression of mRNA for the copper-dependent enzyme, lysyl oxidase, and the effect of copper and/or copper chelating thiomolybdates on FSH-induced differentiation of bovine granulosa cells cultured in serum-free media.…”