This abattoir survey measured copper in the livers of 510 cull cattle from across Great Britain and grouped the results by diagnostic category. More than half of the livers were above the laboratory’s normal range, and dairy breeds carried higher copper than beef breeds. The authors attribute the pattern to current feeding and supplementation practice rather than underlying soil copper, which showed no relationship with liver copper.
Key numbers
All liver values are µmol/kg dry matter (the PDF prints the micro sign in a Greek font; the abstract renders it as µmol/kg).
- Of 510 livers, 52.2% were above the “normal” range (more than 5618 µmol/kg dry matter) (Results, p. 2).
- Above the AHVLA reference range (more than 8000 µmol/kg dry matter): Holstein-Friesian dairy cows 149 of 389 (38.3%); other dairy cows 12 of 30 (40.0%); beef cows 13 of 77 (16.9%); bulls 3 of 14 (21.4%); all animals 177 of 510 (34.7%) (Table 1, p. 2).
- In the “toxic” category (14047 to 44952 µmol/kg dry matter): 38 of 510 (7.5%); “deficient” (less than 281 µmol/kg dry matter): 37 of 510 (7.3%) (Table 1, p. 2).
- 16.3% of cattle were below the normal range (less than 1405 µmol/kg dry matter), mostly beef breeds or bulls (Discussion, p. 4).
- The paper states that the maximum dietary copper permitted without veterinary prescription under domestic and EU legislation is 35 mg/kg at 88% dry matter, equating to 40 mg/kg of total diet dry matter, and that the guidance-note recommendation for total copper is 20 mg/kg dry matter (Background, p. 1).
- Liver dry matter was taken as 280 g/kg for converting category limits to a dry basis (Methods, p. 2).
Methods (brief)
Liver samples from the caudal edge of the left lobe were frozen, freeze-dried, microwave-digested in nitric acid and hydrogen peroxide, and analyzed by ICP-MS with collision-cell mode; blanks and NIST SRM 1577c bovine liver ran with each digestion run. Breed, sex, age and holding location came from the British Cattle Movement Service. Category distributions were compared with chi-square tests.
Evidence fitness
Supports the distribution of copper loading in UK cull-cattle liver and the link between high liver copper and feed supplementation practice. It reports category counts, not means or a concentration distribution of liver sold as food, and it makes no human intake or health-risk estimate.
Limitations
Samples came from a single abattoir over three days, and cull animals are not the whole herd or the retail liver supply. Nutritional histories were unknown. Results are reported only as diagnostic categories on a dry-matter basis.
Related evidence
Update history
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