The theme of “sharing toxicological knowledge for healthy life and environment” was key at the 8th Congress of Toxicology in Developing Countries, held in Bangkok, Thailand, where attendees focused on the risks of heavy metal contamination in pork offal during a presentation given by Animine in association with Mahidol University (Thailand) and the French Institute for the Pig and Pork Industry.
Heavy metals (mainly cadmium, lead and arsenic) in animal feeds can originate either from contaminated feedstuffs or from supplemental sources of additives, especially essential trace minerals like zinc and copper, according to Animine. When contaminated diets are fed to pigs, heavy metals accumulate preferentially in the storage organs. Recent analytical surveys showed that one-fourth of pig kidneys in Thailand were above the regulatory limit in cadmium concentration. The percentage of kidneys unsafe for human consumption could not be solely explained by potential Cd-polluted areas, but may originate from contaminated sources of trace mineral supplements.
Recent analysis with batches of zinc oxide products utilized in pig diets showed very high levels of contaminants. Supplementation of piglet feeds with zinc oxide at pharmacological levels, about 25 times more than the nutritional requirements, is common to secure growth performance and/or reduce post weaning diarrhea of the piglets, said Animine in its presentation. Although the period of supplementation is early in the pig life, the very long biological half-life of heavy metals causes a risk of high Cd levels in the organs at the slaughter.