There has been much outcry over revelations that Chinese businesses fraudulently included melamine and cyanuric acid in animal feeds. But we should be at least as concerned about the "business as usual" ingredients that are routinely fed to the animals we eat.
Today in the United States, almost all animals intended for human consumption are produced within an industrial system reliant on feeds that include a variety of dubious ingredients. Chicken manure, factory wastes, plastics, pet food waste and cyanuric acid - all are commonly deemed acceptable ingredients in feed for animals that end up on our dinner tables.
We now know that it is common practice in China to boost animal feed protein readings by adding the industrial waste products melamine (a nitrogen-rich compound used to make plastics and fertilizer) and cyanuric acid (often used in the United States as a stabilizer for chlorinated pool water). Although neither chemical is very harmful alone, the combination appears to form crystals responsible for kidney failure in pets.
These chemicals got into feed for at least 20 million U.S. chickens, 56,000 hogs and an as yet unknown number of farmed fish destined for human consumption. According to government reports, humans have probably consumed up to 3 million chickens and 345 hogs that ate the chemicals, and all affected hogs were just cleared for human consumption. Government reviews suggest that the risk from this consumption is minimal. Perhaps we got "lucky" this time.
So let us learn from the experience. China is far from alone in allowing waste streams and substances that cannot be categorized as "food" to be fed to hogs, chickens, fish and other animals that people eat - or to animals that produce our milk and eggs.
A paper this month in Environmental Health Perspectives examined the health effects of ingredients in feed consumed by animals destined for the slaughterhouse. It found that animals eat rendered remains from slaughtered animals (including those excluded from human consumption); animal excrement; animal fats that may contain dioxins and PCBs; food contaminated with rodent and roach excreta; byproducts from drug manufacture; and plastics.
