This page collects evidence on metals in livestock feed, feed ingredients, mineral supplements and premixes. Findings retain the animal species, feed form, sampling period, analytical basis and reporting limits used in each study.
Evidence boundaries
A feed concentration does not establish the concentration in meat, milk or eggs. Such a conclusion requires paired measurements or a supported transfer model. Premixes and mineral concentrates also need their intended inclusion rates before they can characterize a complete ration.
Texas feed surveillance, fiscal years 2011–2015
Dai et al. analyzed officially collected feed ingredients, mineral products, premixes and feeds from Texas manufacturing and distribution establishments. Their stated total is 564 samples; Table 1 sums to 565. The source interval is October 1, 2010 through May 31, 2015. ICP optical emission was used initially, followed by ICP mass spectrometry and a wider metal panel. Increasing detection rates therefore do not establish a comparable temporal trend. Heavy Metal Contamination of Animal Feed in Texas
| Fiscal year | Samples in Table 1 | Samples with any analyzed metal detected |
|---|---|---|
| 2011 | 81 | 23 |
| 2012 | 73 | 62 |
| 2013 | 113 | 112 |
| 2014 | 145 | 140 |
| 2015 | 153 | 152 |
The annual totals above sum the source’s feed-type rows; the paper’s stated total and its 2012 percentage are inconsistent with those rows. These counts reflect different feed categories and metal panels across years. They are not prevalence estimates for a fixed population. Heavy Metal Contamination of Animal Feed in Texas
Feed-form and analytical coverage
The survey covers beef-cattle, horse, poultry, sheep/goat, swine and wildlife feed categories, fish meal, liquid feeds, minerals and premixes. Element-specific sample counts differ. All ten measured elements—arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium and thallium—retain their source-defined groups and reported statistics. Below-quantitation values were replaced with zero for the authors’ descriptive analysis. Heavy Metal Contamination of Animal Feed in Texas
Selenium illustrates the distinction between a feed ingredient and a complete ration: source-reported premix mean was 74.6 mg/kg, SD 69.5 and median 59.5 (N=28), while fish-meal mean was 1.1 mg/kg, SD 1.5 and median zero (N=22). Intended inclusion rates and elemental forms were not resolved for each summary group. These figures cannot be treated as concentrations in the final diet or in animal-derived foods. Heavy Metal Contamination of Animal Feed in Texas
Limitations and source discrepancies
The source has a sample-count mismatch, contradictory cadmium units, an impossible horse-feed lead median, conflicting molybdenum footnotes and mislabeled histogram panels. Its analytical limits and source-zero substitutions must stay attached to the data. Regulatory and nutritional comparators quoted in the paper have not been verified from their primary instruments. No edible tissue, milk, egg or pet-food product was sampled. Heavy Metal Contamination of Animal Feed in Texas
References
Works cited in this page’s text, in first-appearance order. Each title links to its source record, which carries the ingest receipt, the extracted values, and the file hash of the document it was built from.
- Heavy Metal Contamination of Animal Feed in TexasPeer-reviewed
Update history
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