Thai authorities find melamine in imported feed

By Jane Byrne

- Last updated on GMT

© istock/luplupme
© istock/luplupme
Thailand’s Department of Livestock Development is to blacklist a Vietnamese supplier as an inspection process reveals melamine tainted feed in an imported shipment, according to the Bangkok Post.

The Thai officials ran laboratory tests on 60 tons of dried squid derived meal imported from a Vietnamese firm and found it was contaminated with, cyanuric acid, which is a structural analogue of melamine.

The Department, according to the media outlet, is to enforce more rigorous checks on feed shipments from Vietnam as a result.

The shipment had been imported by two Thai companies. But the level of melamine present is not clear from the reports.

Melamine can be present at low levels in food and feed mostly from its legal use as a food contact material in laminates and plastics, as a trace contaminant in nitrogen supplements used in animal feeds, and as a metabolite of the pesticide cyromazine, according to a study by Dorne et al, published in 2013 in the journal Toxicology and Applied Pharmacology​.  

Deaths from adulterated products

In 2007, contaminated pet-food with melamine​ ​led to the death of hundreds of cats and dogs in the US. 

The US Food and Drug Administration (FDA) became aware that certain pet foods were sickening and killing the pets and, in March 2007, it found melamine contaminants in vegetable proteins imported into the US from China and used as ingredients in pet food. 

Some of the tainted pet food was also used to produce feed for livestock and fish. 

In 2008, as a result of a joint investigation by the FDA and the US Department of Agriculture (USDA), two Chinese nationals and the businesses they operated, along with US company, ChemNutra, and its top two executives, were indicted by a federal grand jury for their roles in a scheme to import products contaminated with melamine.

Adulteration of milk with melamine resulted in hospitalization and deaths of children in China in 2008. Following these incidents, the tolerable daily intake for melamine was re-evaluated by the FDA, the World Health Organization (WHO), and the European Food Safety Authority (EFSA).​ ​The international feed and food safety agencies also established maximum residual limits of melamine in feed.


A study by Su et al​ in 2014 noted that due to its high nitrogen content, melamine may be illegally added to animal feeds to increase their apparent protein contents.

The authors said that when melamine and cyanuric acid combine, they form white melamine cyanurate crystals that instantly precipitate in the kidneys, thus causing renal failure.

Though various toxicology studies have found melamine toxicity in mammals is very low, those researchers said the risk assessment for melamine is complicated by the fact that it can exert differential toxicity in various animal species.

“Although melamine has been found only in the wheat gluten, rice protein concentrate, and corn gluten used in animal feed, it cannot be assumed that melamine has not been added to other protein sources intended to be used as feed 

In this regard, the development of effective methods to monitor melamine in animal feed has become necessary and urgent, and therefore, it is worth investigating both the current and alternative techniques used to detect and determine the concentration of melamine in feed,”​ noted Su et al.

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