What Is Animal Rendering?

Animal rendering is a process by which animal waste and dead animals are used to create a new, usable product. These waste and byproduct materials can be classified as either edible or inedible. Rendering products are often used in animal feed. Most sources for animal rendering are farms, ranches and food waste from restaurants or stores.

Process

• Rendering plants operate with different specialties. Plants can recycle animal products into meat meal, poultry meal, grease, beef fat or chicken fat. According to the Environmental Protection Agency, plants that receive products from slaughterhouses and processing plants for poultry are known as integrated rendering plants while plants that use materials from other sources are called independent rendering plants. There are two types of processes for animal rendering: edible and inedible rendering.

Edible Rendering

• Tallow is used in soap products.

  Edible rendering is a process of converting fat trimmings into a usable food product, such as lard and tallow (cattle or sheep fat). Tallow is most commonly used in soap and candles. However, tallow can also be used as a form of cooking oil since it doesn't require refrigeration. Fat trimmings are ground up and then placed into a melt tank. The fat from the tank is pumped into a disintegrator. The fat is separated from any solid materials and water until eventually only the fat remains.

Inedible Rendering

• Inedible waste products are converted into meal, which is a main component in animal feed and pet food. Pet food is made from waste products that include chicken parts, meat meal from cow hooves and gelatin. There are two methods for inedible rendering: the dry method and the wet method. The dry method continually processes materials by dehydrating the materials until only the fat remains. The wet method removes fat from waste by boiling the waste in water. According to the Environmental Protection Agency, the wet process uses steam to cook waste products until the fat is released.

Advantages

• Recycling animal products helps to dispose of waste without adversely affecting the environment. For example, many slaughterhouses would prefer not to rely on using incinerators or compost to get rid of animal waste. Moreover, animals that die, before reaching slaughterhouses, can also be rendered, which helps reduce the cost of paying for the animal to be removed from a farm.

Concerns

• Compounds can be released into the air, during the rendering process, producing odors in neighborhoods close to the plants. Depending on the type of rendering plant, emission control is regulated to help prevent the accumulation of odors through ventilators and scrubbing.

Bovine Spongiform Encephalopathy

• The discovery of BSE in cows raises questions regarding rendering practices.

  If there are unsanitary cleaning methods for inedible waste products, meal for cow feed can become tainted with bovine spongiform encephalopathy. BSE, also known as mad cow disease, occurs in cows if they eat products that are tainted with infected proteins, such as the brains and spinal cords of animals. Since this discovery, rendering practices have been altered to enforce stricter sanitation methods. According to the U.S. Food and Drug Administration, the use of spinal cords and brains from cattle older than 30 months is strictly prohibited in the hopes of preventing the spread of BSE through animal feed.