Monitoring trace minerals and heavy metals in liver of free-living large herbivores in the Netherlands.
Authors: Marcelino Inês, Monti Gustavo, Cornelissen Perry, Bassingthwaighte Evelyn, Het Lam Jasper, van der Merwe Deon, van der Poel Wim H M
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: Trace Mineral Monitoring in Free-Living Herbivores Long-term post-mortem liver sampling from Heck cattle, Konik horses and red deer at Oostvaardersplassen nature reserve in the Netherlands has yielded the first comprehensive trace element reference intervals for these species, established through inductively coupled plasma mass spectrometry analysis of arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, vanadium and zinc. The researchers identified distinct species-specific elemental profiles—notably elevated copper in red deer and raised iron and lead concentrations in horses—alongside temporal declines in iron and lead across all three species, with additional seasonal and age-related variations documented throughout the monitoring programme. Critical differences emerged between the derived reference intervals and existing livestock standards, particularly for copper and selenium, demonstrating that extrapolating domestic animal mineral thresholds to free-living populations introduces significant assessment error. For equine practitioners and those advising on horse health in minimally managed systems, these findings underscore the inadequacy of conventional reference ranges and suggest that mineral status interpretation in semi-feral or grazing populations requires contextual, species-specific benchmarks rather than standardised livestock values. This longitudinal environmental dataset provides essential baseline data for tracking long-term changes in mineral availability and contaminant burden within pasture-based systems, informing both individual animal health decisions and broader reserve management strategies across Europe.
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Practical Takeaways
- •Standard livestock reference intervals for minerals are not appropriate for free-living or minimally managed horses; establish species and context-specific baselines for your population
- •Monitor temporal trends in heavy metals like lead and iron in your herd as environmental exposures may change over time and affect health outcomes
- •Consider seasonal and age factors when interpreting trace mineral levels in horses—single point-in-time measurements may not represent true status
Key Findings
- •Species-specific trace element profiles identified with red deer showing higher copper and horses elevated iron and lead levels
- •Temporal declines in iron and lead concentrations observed across all species throughout monitoring period
- •Reference intervals for free-living herbivores differ significantly from livestock standards, particularly for copper and selenium
- •Seasonal and age-related variations in liver trace element concentrations demonstrated across Heck cattle, Konik horses, and red deer