Consumer demand for B.A.R.F. (biologically appropriate raw feeding) is increasing as a means to provide the best nutrition for pets. Because of this, raw food for cats and dogs has become a growing trend and the quickest developing sector within the pet food manufacturing industry. Yet, just because pet food is raw does not mean it is unprocessed. Special processing must take place to ensure a high level of nutrients remains in the product while also preventing contamination of the raw pet food. Manufacturing equipment like air classifying mills is an integral part of this process, and their design is an important element in reducing raw meats into well-balanced meals for pets. 

Pet Food Manufacturing: Raw Diets for Cats & Dogs

As domestic dogs and cats descended from wild animals, it makes sense they would benefit from a diet of raw meat. However, feeding raw meat and bones from the local grocery store is risky. Retail supermarkets assume the raw meat bought from them will be used for human consumption and cooked to appropriate temperatures to reduce risk from bacteria and other pathogens.  

Benefits of Raw Meat Diets for Pets

Pets like cats and dogs have much shorter digestive systems than humans. Pets’ bodies are designed to ingest their raw meat and bones from prey without fillers like grains, a common element in conventionally processed pet food. Manufacturing pet food by more traditional means also includes artificial additives, which make nutrients more difficult for pets to absorb. 

Raw food diets improve a pet’s:  

  • Bone structure, with puppies raised on raw diets exhibiting fewer bone issues later in life. 
  • Coat and skin due to higher protein intake, making a pet’s coat healthier and resulting in less shedding. 
  • Dental hygiene by eliminating carbohydrates, starch, and processed fat that can lead to plaque buildup, gum disease, bad breath, and sometimes even tooth extractions. 
  • Digestion by delivering readily absorbable nutrients and healthy bacteria, as dogs and cats do not produce an enzyme called amylase, which helps animals digest grain.
  • Excretions by allowing the animal’s body to use more nutrients contained in the food, making their feces smaller, firmer and less smelly. 
  • Immune system by supplying a diet rich in nutrients and fatty acids that boost the body’s response to disease. 
  • Joints later in life, as raw diets have high Omega-3 levels, which reduce inflammation caused by conditions like arthritis. 
  • Muscle tone through increased protein intake, while also greatly lowering the risk of obesity posed by a high-carbohydrate diet. 
  • Reaction to allergens like grain or fillers often found in conventional kibbles that can cause discharge from the eyes or constant scratching.  

Difference in Diets Between Cats & Dogs

The dietary requirements for dogs and cats are different. While cats biologically require meat in their diets as obligate carnivores, dogs are actually omnivores that need both meat and vegetables. For this reason, cat food has much higher levels of animal protein, which makes its taste and smell meatier. This is why dogs tend to be partial to cat food, as it contains more meat-based protein. Though dogs crave meat, this does not mean cat food should be part of their diet. For this reason, pet food manufacturing must differentiate between what cats and dogs eat, even for raw pet food diets. 

Which Machine Do I Need?

Using Air Classifying Mills in Pet Food Manufacturing 

When it comes to processing pet food, manufacturing equipment like air classifying mills work ideally for this purpose. This is especially true for high-quality raw pet foods, which benefit from specific aspects of the machine’s design and operation not present in other mills. Air classifying mills prevent products from degrading by conveying them via pneumatic means rather than mechanically. Air conveyancing also has another added benefit, preventing thermal degradation by shielding it from heat generated by the machinery. 

Air classifying mills work by combining dual-stage grinding in a closed circuit with an inter-stage air classifier. Being an all-in-one unit, the internal air classifier recirculates back larger particles to the grinding zone, ensuring optimum particle size of the end product. It also allows for narrower particle distribution while handling materials that are difficult to grind better than other mills or single-pass reduction equipment. 

To grind and reduce material, the product is fed through a rotary feed valve into the air classifying mill grinding chamber. It processes pet food through high-speed grinding media, using centrifugal force to throw product against the grinding chamber wall, causing it to break down further. 

How Rotary Sifters Work Together with Air Classifying Mills

An important element within production lines that utilize air classifying mills is the rotary sifter, also known as a rotary sieve or centrifugal sifter. Rotary sifters are designed to work with air classifying mills when grinding bulk raw material. The pet food manufacturing process sifts out foreign material or particulates like insects, plastic, or string. By harnessing the centrifugal force of the rotating machinery, it fluidizes and accelerates the raw pet food to the screen’s surface. From there, it moves the material into the screening chamber, where particles are thrown outward by rotor paddles. Meanwhile, finer particles pass through the screen and into a hopper. The rotor paddles force coarser material towards the end of the chamber, expelling it into a separate hopper. This results in a natural vibration that enhances the free flow of material. 

Challenges in Pet Food Manufacturing

Manufacturing pet food poses challenges similar to that of processing food products for humans. The presence of pathogens is a problem endemic to the pet food manufacturing industry. In fact, of the twelve pet food recalls in 2021 (as of mid-November), nine resulted from positive results for bacteria like salmonella and listeria, mold or aflatoxin, a mold by product. These toxins can have detrimental – and even deadly – effects on the pets that ingest contaminated pet food. 

However, concerns about contaminated pet food affect more than just the pets. They also affect the reputations of the companies that make them. In one instance, customers shared photos of moldy dog treats on Instagram. At the same time, another company that dragged its feet in a similar case saw multiple Twitter users tweet photos of the contaminated dog treats for months before its recall. Such recalls are extremely costly for pet food brands.  

This is not just a problem with conventional pet food manufacturing but also raw pet food as well. One 2021 recall involved frozen raw dog food, triggered by FDA (Food and Drug Administration) testing of product samples, which revealed positive results for salmonella and listeria. 

To minimize the risk of contamination, producers should focus on maintaining a strict hygiene and sanitation regime in their manufacturing process. System design should segregate employees from raw materials, while production lines and equipment should be regularly sterilized, including machinery used in conveyancing. An air classifying mill’s specialized capabilities are ideal for pet food manufacturing. An air classifying mill’s pneumatic conveying system and enclosed design keep workers and products separate, contributing to worker safety and product hygiene. This is true not only with raw pet food manufacturing but also with conventional processing of pet food.