Identifying sources of metal exposure in organic and conventional dairy farming.

Chemosphere. 2017 Oct;185:1048-1055. doi: 10.1016/j.chemosphere.2017.07.112. Epub 2017 Jul 24. López-Alonso M1, Rey-Crespo F2, Herrero-Latorre C3, Miranda M4. Author information 1 Departamento de Patología Animal, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain. Electronic address: marta.lopez.alonso@usc.es. 2 Departamento de Patología Animal, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain; Centro Tecnológico Agroalimentario de Lugo (CETAL), 27002 Lugo, Spain. Electronic address: franreic@hotmail.com. 3 Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo, Spain. Electronic address: carlos.herrero@usc.es. 4 Departamento de Anatomía, Producción Animal y Ciencias Clínicas Veterinarias, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain. Electronic address: marta.miranda@usc.es. Abstract In humans the main route of exposure to toxic metals is through the diet, and there is therefore a clear need for this source of contamination to be minimized, particularly in food of animal origin. For this purpose, the various sources of toxic metals in livestock farming (which vary depending on the production system) must be taken into account. The objectives of the present study were to establish the profile of metal exposure in dairy cattle in Spain and to determine, by chemometric (multivariate statistical) analysis, any differences between organic and conventional systems. Blood samples from 522 cows (341 from organic farms and 181 from conventional farms) were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of 14 elements: As, Cd, Co, Cr, Cu, Fe, Hg, I, Mn, Mo, Ni, Pb, Se and Zn. In conventional systems the generally high and balanced trace element concentrations in the mineral-supplemented concentrate feed strongly determined the metal status of the cattle. However, in organic systems, soil ingestion was an important contributing factor. Our results demonstrate that general information about the effects of mineral supplementation in conventional farming cannot be directly extrapolated to organic farming and special attention should be given to the contribution of ingestion of soil during grazing and/or ingestion of soil contaminated forage. Copyright © 2017 Elsevier Ltd. All rights reserved. KEYWORDS: Chemometric analysis; Conventional farming; Dairy cattle; Metals; Organic farming PMID: 28764100 DOI: 10.1016/j.chemosphere.2017.07.112 [Indexed for MEDLINE] Share on FacebookShare on TwitterShare on Google+