Effect of High-Level Copper Feeding on the Sulfur Amino Acid Need of Chicks Fed Corn-Soybean Meal and Purified Crystalline Amino Acid Diets

Abstract

Supplementation of a corn-soybean meal diet with .05% methionine maximized gain and feed efficiency of three-week-old chicks fed copper at either 0 or 250 mg/kg. With copper present at 500 mg/kg, the supplemental methionine requirement was in excess of .10%. Liver copper stores of chicks fed copper at 250 mg/kg declined linearly as supplemental methionine level increased, but methionine level had no effect on liver copper when chicks were fed 500 mg/kg copper. Liver copper accumulation did not occur in chicks fed 250 mg/kg copper when supplemental sulfur was provided as a combination of .05% methionine and 1800 mg/kg sulfide. Irrespective of methionine level, sulfide addition reduced liver copper by one-half in birds fed 500 mg/kg copper. Chicks fed the purified diet were appreciably more susceptible to copper toxicity than those fed the corn-soybean meal diet. Chicks fed the purified diet without supplemental copper required .52% sulfur amino acids (SAA). Chicks fed copper at 250 and 500 mg/kg required .65 and .70 SAA, respectively, although gain and feed efficiency were still depressed when compared with the performance of the control birds. Higher levels of methionine failed to restore growth rates to those achieved with birds fed no supplemental copper. Supplementing the copper-containing diets with up to 1.6% cystine improved performance some but failed to completely overcome the growth depressing effect of copper at 500 mg/kg. Results of additional studies indicated that the purified diet containing .70% SAA and 500 mg/kg copper was nutritionally adequate and that the marked toxicity of copper when fed in the purified diet was due to the chemical nature of the diet rather than to any specific copper-induced nutritional deficiencies.

Eimeria Acervulina Infection in Chicks Fed Excess Copper in the Presence or Absence of Excess Dietary Methionine

“…However, we were unable to demonstrate that excess supplemental methionine could amelioriate the adverse effects of a Cu toxicity. This does not agree with the recent reports of Maurice (1978, 1979) and Robbins and Baker (1980a). Part of the discrepancy may be explained by the complete SAA adequacy of our basal diet.…”

“…The basal diet used in our experiments contained very little supplemental inorganic sulfur. This might explain a portion of the discrepancy between our results and the results of Maurice (1978, 1979), and Robbins and Baker (1980a).…”

“…Kline et al (1973), Cromwell et al (1978) and Prince et al (1979) have shown that sulfide will prevent liver Cu accumulation in swine fed high levels of Cu. Similarly, Robbins and Baker (1980a) reported that sulfide (1,800 mg/kg) reduced liver Cu accumulation in chicks and that methionine did not completely alleviate the adverse effects of a Cu toxicity unless the diet contained sulfide. Jensen and Maurice (1979) reported sodium sulfate (.381%) was partially effective in preventing Cu toxicity in chicks, but Robbins and Baker (1980b) could not confirm this result using potassium sulfate (.14%) in a semipurified diet.…”

Excess Dietary Methionine Decreases Indices of Copper Status in the Rat

“…Methionine has been used to treat the toxic symptoms caused by excessive inges tion of Cu in chicks and chelation reactions, which result in less efficient absorption and/or utilisation of Cu, appear to be the protective mechanisms involved [20], Simi larly excessive Cu ingestion can impair me thionine utilization and increase the dietary requirement of chicks for sulfur amino acids [21]. The current work shows clearly that methionine supplementation decreases tis sue Cu levels and the activities of several Cucontaining enzymes in the rat.…”

Interaction of Dietary Nutrient Concentration and Supplemental Copper on Chick Performance and Tissue Copper Concentrations

“…However, Jensen and Maurice (1979) and Harms (1979, 1984) were able to show that the growth-depressing effect of Cu could be alleviated with supplemental methionine (MET). Robbins and Baker (1980a) demonstrated that supplemental amino acids, minerals, and vitamins could overcome the growth depression observed when chicks were fed 500 mg/kg Cu in a purified diet. These results led Christmas and Harms (1984) to postulate that the growth de- pression observed in chicks fed high levels of Cu may be the result of two separate factors: 1) a nutrient deficiency resulting from reduced feed intake, and 2) Cu toxicosis per se.…”