Amelioration of oral copper toxicity in chicks by dietary additions of ascorbic acid, cysteine and zinc

Michael E. Persia, Carl M. Parsons, David H. Baker

Research output: Contribution to journalArticlepeer-review


Four experiments were conducted to evaluate the interrelationship of L-ascorbic acid, L-cysteine and Zn for amelioration of Cu toxicity in chicks. Chicks were fed a corn-soybean meal diet with 1,000 mg Cu (CuSO4 · 5H2O)/kg to produce Cu toxicity. Single dietary additions and two-way combinations of ascorbic acid (1,000 mg/kg), cysteine (0.5 g/100 g) and Zn (1,000 mg/kg) reduced liver Cu accumulation, with cysteine resulting in the largest response. Although supplemental Zn from ZnSO4 · 7H2O reduced liver Cu concentrations, it also reduced chick weight gain and food intake. Experiment 2 tested a range of cysteine and Zn levels to determine their effects on Cu toxicity in chicks. Supplemental Zn levels as low as 500 mg/kg reduced growth, but a cysteine level as low as 0.1 g/100 g increased chick weight gain and reduced liver Cu. Experiment 3 evaluated two Zn sources to determine if Zn source was affecting weight gain of chicks fed high Cu diets. There was a reduction in chick weight gain with 1,000 mg Zn/kg from Zn sulfate, but no reduction in weight gain with the same level of Zn from Zn oxide. In Experiment 4, 1,000 mg ascorbic acid/kg, 0.05 g/100 g cysteine and 1,000 mg Zn/kg from Zn oxide were tested in a 2 x 2 x 2 factorial. As in Experiment 1, ascorbic acid, cysteine and Zn were all effective in reducing liver Cu. The results suggested that L-cysteine was more effective than either L-ascorbate or Zn in ameliorating Cu toxicity, but a lower dose of cysteine together with pharmacologic additions of ascorbate and Zn (from ZnO) may be just as effective.

Original languageEnglish (US)
Pages (from-to)1709-1718
Number of pages10
JournalNutrition Research
Issue number12
StatePublished - Dec 2003


  • Ascorbic acid
  • Chick
  • Copper toxicity
  • Cysteine
  • Wilson's disease
  • Zinc

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Nutrition and Dietetics


Dive into the research topics of 'Amelioration of oral copper toxicity in chicks by dietary additions of ascorbic acid, cysteine and zinc'. Together they form a unique fingerprint.

Cite this