Contamination and Animal Feed

Today’s consumers are very interested in the safety of our food supply. They also show a growing concern when it comes to the food supply provided to the livestock our farmers and ranchers raise, and even more, animal food available to their pet family members in their own homes.

Over the years, several high-profile events have raised the awareness of animal food safety that spotlighted the risks to our food chain. The bovine spongiform encephalopathy outbreak in the 1990s, better known as BSE, and the melamine contamination in pet food in 2007 are two well-known and publicized past events in the industry. Although rare, these events still gain the public’s attention; but in fact, many more million tons of feed is manufactured safely each year.

Last year, there was more than 150 million tons of animal feed manufactured by 6,700 feed mills in the U.S. This does not include more than 8 million tons of pet food manufactured in the U.S. These animal feeds required multiple raw materials mostly from crops grown within the U.S. or Canada.

Many of the ingredients used by the animal feed industry are materials not used for human consumption or are products remaining after processing materials for human food, known as co-products for animal feed. This includes materials such as bakery byproducts, dried distillers grains (from beverage and industrial ethanol production), soybean and cottonseed meals and hulls (from vegetable oil processing), molasses (from sugar production), and peanut skins.

In addition, most animal feeds are manufactured as complete diets for animals and fed as the sole food for animals. Thus, the type of animal and the animal’s life stage impacts the nutritional fortification of the feed to ensure the animal’s needs are provided.

There have been almost 500 recalls of animal foods from 2013 to the present. Of these recalls, 95 percent were pet products, primarily due to suspected Salmonella contamination or risk (89 percent). With the majority of pet foods fed within the home, microbial contamination is a major concern for the industry to ensure the safety of the pet owners. For livestock, such as cattle, poultry, and pigs, Salmonella contamination is not as worrisome of an issue, as the feeding environment and the feed processing do not pose a food safety risk for humans.

Industry is faced with a variety of potential contaminants within animal feed, mostly the contaminants come from incoming materials. It is important to assess the severity and probability of the potential contaminations in order to determine the actions required, if any, to control the potential risk. The principles of Hazard Analysis and Critical Control Points, or HACCP, program are useful in order to manage the potential risks from contamination, which can be divided into physical, chemical, and biological risks.

The Risks

Physical. Bulk materials are the most common source of physical contamination. Proper inspection prior to unloading is the first step in minimizing the risk of contamination. A bulk material may be transported several times (harvest, rail, truck, etc.) before reaching a feed mill for processing into animal feed. Thus, materials are screened to remove debris that does not belong in the ingredient and may have been introduced during transport. Magnets are used to remove ferrous materials throughout the manufacturing process, including during receiving. Most physical contaminants do not create food safety risks for the animal or humans.

Chemical. The highest potential risks for animal food safety come from chemical contamination. The most common risk is mycotoxins, which form naturally within grains.