For the most recent description of the pet food manufacturing process, visit the French manufacturer of dog food.
Pet food is a specialty food for pets that is formulated according to their nutritional needs. Pet foods generally include meat, meat by-products, cereals, cereals, cereals, cereals, cereals, vitamins and minerals. In France, about 300 manufacturers produce more than 7 million tonnes of pet food every year, one of the largest categories of packaged food. Pet owners can choose from more than 3,000 different pet food products, including dry, canned and semi-wet foods, as well as snacks such as cookies, croquettes and treats. In the 1990s, this $8 billion industry fed 52 million dogs and 63 million cats in France.
Commercially produced pet food is derived from a dry biscuit-type dog food developed in England in 1860. Shortly thereafter, manufacturers produced more sophisticated formulas, which included nutrients considered essential for dogs at the time. At the beginning of the 20th century, pre-packaged pet food was also available in France. At first, they consisted mainly of dry cereals, but after World War I, dog food made from canned horse meat was available. The 1930s saw the introduction of canned cat food and dry meat meal-type dog food. Innovations in the 1960s included dry cat food, expanded dry dog food and semi-wet pet food.
In the early 1980s, pet food market trends included increased demand for dry food and less canned food. Research has suggested that a soft diet of canned dog food causes gum disease more quickly than dry food. In general, growing public awareness of health has led to increased interest in more nutritious and scientific formulas for pet foods, such as life cycle products for younger and aging pets, and therapeutic foods for specific animal health problems, such as weight loss and urinary problems. Pet food producers were also more likely to use less fat and tallow and more protein-rich tissues. Finally, the pet snack category has gained popularity with products such as dried meat snacks, sausage pieces, cookies and cookie pieces called croquettes.
The main ingredients of pet food are by-products of meat, poultry, seafood, feed grains and soybean meal. Animals used for rendering include livestock, horses and domestic animals that have been put to sleep. The National Animal Control Association has estimated that approximately 5 million pets were shipped to rendering plants each year and recycled into pet food during the 1990s. They are generally listed as meat or bone meal in ingredient lists.
Animal parts used for pet food may include damaged carcass parts, bones and cheek meat, as well as organs such as the intestines, kidneys, liver, lungs, udders, spleen and gastric tissue. Cereals, such as soybean flour, corn flour, crushed wheat and barley, are often used to improve the consistency of the product as well as to reduce the cost of raw materials. Liquid ingredients may include water, meat broth or blood. Salt, preservatives, stabilizers and gelling agents are often required. Gelling agents provide greater homogeneity during processing and also control humidity.
They include bean and guar gums, cellulose, carrageenan and other starches and thickeners. Palatability can be improved with yeast, protein, fat, fish-soluble, sweeteners or concentrated flavours called “digested”. Artificial flavours are generally not used, but smoke or bacon flavours can be added to some sweets. Most manufacturers supplement pet food with vitamins and minerals, as some of them can be lost during processing.
Ingredients vary somewhat depending on the type of pet food. The fundamental difference between canned and dry pet food is the amount of moisture. Canned foods contain between 70 and 80% moisture, since they are generally made from fresh meat products, while dry pet food contains no more than 10%. Other ingredients used in dry foods include corn gluten, meat and bone meal, animal fats and oils. To obtain a texture similar to that of meat, dry foods require more starchy ingredients or starch, protein adhesives such as collagen, albumin and casein and plasticizers. Semi-wet pet foods usually require binders, which come from various sources, such as gels, cereal flours, sulphur amino acids, lower aLkyl mercaptans, lower alkyl sulphides and disulphides, salts and thiamine. Semi-wet products may also contain soy flakes, bran flakes, soluble carbohydrates, emulsifiers, stabilizers, skim milk powder and whey powder.
Antioxidants are often used to delay the oxidation and rancidity of fats. These include butylated anisole hydroxy (BHA), butylated toluene hydroxy (BHT) and tocopherol. To prevent mould and bacterial growth, producers use either sucrose, propylene glycol, sorbic acid or potassium and calcium sorbates.
The production of dog food
With the exception of ingredients, the general manufacturing process for pet foods is similar to that for processed foods. Meat products used in petfood must first be melted or processed to separate water, fat and protein, including soft (viscera) and hard (e.g. bones and hooves) offal. In general, meat is returned by outside companies and shipped to pet food manufacturers. Meat products for canned food must be delivered fresh and used within three days. Frozen meat products can be used for dry food.
The manufacturing process includes the crushing and cooking of the meat and meat by-products. Then the meat is mixed with the other and if the recipe requires it, the mixture is shaped into the appropriate shapes. The finished product is packaged in containers and shipped to distributors.Innovations in the processing and packaging of pet food have resulted in better quality products with a longer shelf life. Vacuum-packed canned dog food has a shelf life of three to five years and is very stable with little or no loss of nutritional value. Dry dog food, on the other hand, has a shelf life of only 10 to 12 months and requires the addition of preservatives, although some manufacturers use natural preservatives such as vitamins E and C.
Rendering of meat
1 In general, rendering is carried out by meat processors. Rendering consists of breaking up the fat cells, either by heat or by enzymatic and solvent extraction, and then drying the residue.
Grinding and pre-cooking of meat
2 The meat products are coarsely ground to the desired texture.
3 To facilitate further processing, the minced meat is cooked in a continuous live steam cooker at the appropriate temperature.
4 Meat products are ground after initial cooking to a more uniform consistency. For semi-wet or chunky foods, batches are deliberately cooked unevenly to create the desired chunky texture.
Mixing and shaping
5 The meat mixture is mixed with other ingredients such as cereals, vitamins and minerals.
6 Dry and semi-moist foods are usually heated so that the mixture will partially dextrine or thicken the starch. To obtain the marbled appearance of real meat, the meat mixture can be cooked unevenly and half of the batch is coloured red and the other half white. Semi-wet foods must be stabilized to retain the right amount of moisture in the dry and semi-wet parts of the food.
7 Dry and semi-moist foods can be extruded under high pressure using an open plate device to obtain the shape and size of the specific product, for example, the shape of cookies, croquettes, meatballs, patties, pellets or slices. An alternative to extrusion is gelatinization and expansion of the mixture. For marbled meat, the mixture of red and white meat is extruded together and broken into pieces.
Packaging and labelling
8 The measured quantities of the product are packaged in appropriate containers. The dry food is poured into pre-printed containers. Wet canned foods are vacuum sealed to reduce oxygen content and prevent fat deterioration in foods.
9 Pet food cans are sterilized by passing them through a retort or heating chamber. The autoclave can be discontinuous or continuous hydrostatic. The cans are heated to about 250°F (121°C) for 80 minutes, but the temperature and cooking time depend on the contents, steam pressure and size of the can.
10 The boxes are quickly cooled to about 38°C (100°FO). Then the boxes are dried and labelled.
11 The containers are packed in corrugated cardboard boxes or wrapped in plastic film in corrugated cardboard trays. The pet food is ready to be shipped to distributors.
Manufacturers of petfood must comply with the rules and regulations established by several European and national bodies. These bodies control the quality of the meat and determine which animals can be used in pet food. Others regulate ingredients by setting maximum and minimum limits for certain nutrients and prohibiting the use of drugs or antibiotics in food, since pet food is sometimes accidentally consumed by children. The work of the associations formed as a non-governmental advisory group with representatives in each state is to register the 3,000 brands and sizes of pet food.
The statement “guaranteed analysis” on pet food labels was created almost a century ago when some manufacturers used unwanted ingredients such as sand or limestone to add weight to their pet food. The guaranteed analysis guarantees minimum percentages of raw protein and raw fat and maximum percentages of raw fibre and moisture. The term “raw” refers to a method of testing the elements. Other guarantees may include minimum amounts of calcium, phosphorus, sodium and linoleic acid in dog food and ash, taurine and magnesium in cat food. The maximum allowable moisture for canned foods is 78%, while dry foods can contain up to 12% moisture.
Proper labelling of pet food is required to provide accurate information to the buyer. The guidelines are established by the FDA’s Center for Veterinary Medicine and AAFCO. Six basic elements must appear on the label: the name of the product, net weight, the name and address of the manufacturer or distributor, a guaranteed analysis, a list of ingredients and nutritional information. The name of the product must accurately describe its content and comply with the “percentage” rules. The “95%” rule requires that if the name of the product suggests that meat, poultry or fish is the main ingredient, as in “Barbara’s Beef Dog Food”, it must contain 95% or more of that ingredient, excluding water used in processing. If two meat ingredients are listed as primary ingredients, both together must be 95%.
The “25%” rule, or “dinner” rule, applies to items such as “chicken dinner”, “meat entrée”, and terms such as tray, formula, nuggets, and so on. It requires that the foods listed represent between 25 and 95% of all ingredients by weight. If there are more than two ingredients in the name, each must have a weight of at least three percent and the primary ingredient must be listed first, as all ingredients on the label must be listed predominantly by weight.
A third rule is the “three percent” rule, or the “with” rule, which applies to minor ingredients listed on the label. For example, “Charlie’s Chicken Cat Food with Cheese” should contain at least three percent cheese. Finally, the “flavour rule” requires that if a flavour ingredient, such as meat meal, is included in the name, it must be detectable. To avoid misleading customers, the word “flavour” must have the same size and style as the corresponding ingredient. Nor should the images on the label be misleading.
All ingredients must correspond to the specific names given in the official AAFCO publication. All preservatives, stabilisers, colours and flavours must comply with the GRAS rule, “Generally Recognized as Safe”. The term “natural” should not apply to products containing artificial flavours, colours or preservatives.
Calories per serving and per container should be indicated in the same way as food for human consumption, in kilocalories per kilogram. Packaging codes must be printed on all containers.
Many of the processes used to make people eat are also used to make pet food: cooking for treats, canning, extruding for dry croquettes, which is also used to make many breakfast cereals, vacuum cooking, which is a gentle cooking similar to that used for some pies, and other techniques.
Dry kibbles provide most of the calories for American pets. Kibbles account for more than 60% of all cat and dog food sales in the United States. Dry products are available in packages ranging from boxes of just over a pound to large bags weighing 40 to 50 pounds.
Dry products are produced by one of several different processes:
Extrusion/expansion (similar to the process used to make some breakfast cereals)
Wet feed for animals
The most familiar form of wet pet food is sold in cans. Innovation in manufacturing processes can lead to the development of new wet products sold in trays and bags, similar to some of the products we eat.
How dog food is made
Although there are many ways to make dry pet food, the most common process used is extrusion. This process was adapted for the manufacture of pet food in the 1950s based on the technology used to manufacture puffed breakfast cereals. The diagram on the manufacture of petfood by extrusion illustrates the process:
The ingredients are combined in a blender. Dry ingredients can be ground before being introduced into wet ingredients. Once mixed, they form a moist paste.
The dough is heated in the preconditioner before being introduced into the extruder.
The extruder, essentially a giant meat mincer, is where the primary cooking phase of dry extruded pet food takes place. The dough is baked under intense heat and pressure as it moves towards the open end of the extruder. At the end of the extruder, the hot dough passes through a mould and a knife (similar to the action of a meat mincer) where the small pieces expand quickly into croquettes once they are under standard air pressure.
The croquettes are dried in the oven until their moisture content is low enough to keep like a cookie or cracker. The oven is followed by a cooling phase.
After cooling, the croquettes can pass through a machine that sprays on a coating, which is usually a flavour enhancer.
The packaging (bags, boxes, sachets, etc.) are filled in the last step with precise quantities in order to respect the weight indicated on the label. The end result is a finished pet food or treat.
How is wet pet food made?
Manufacturers of pet food are required to follow the same federal regulations for the manufacture of wet pet food (such as canned, bagged and tray products) as manufacturers of human food (21 CFR Part 113).
Clean empty containers (cans, bags, trays, etc.) are filled to specific quantities to respect the weight indicated on the label.
Lids are applied, if applicable, and containers are sealed.
Sealed containers are cooked at a specified temperature for a desired time to destroy all living organisms (bacteria, viruses, moulds) that could otherwise grow in the sealed container and cause illness in people or pets.
Once cooled, the labels are applied to the containers, resulting in wet finished products.
Regulation of pet food
Pet food is one of the most regulated products in grocery stores. Federal and state laws and regulations apply to various aspects of pet food, including ingredients, manufacturing processes and labelling.
- Products must be pure and healthy
- Products must be free of harmful or deleterious substances.
- Products must be accurately labelled.
All pet food plants are subject to inspection by the FDA and state regulatory authorities. In addition, State control authorities have the power to test pet food ingredients and finished products at any time to confirm that they comply with the guaranteed nutritional content indicated on the label and to verify that they do not contain any undesirable substances. State regulatory authorities have the power to issue an order opposing the sale if they find sufficient grounds, such as non-compliance with the nutrition guarantee or labelling claims. The FDA has the authority to issue a warning to consumers if it concludes that a product on the market is dangerous and should be withdrawn from the market.
Most states require, under their feed laws and regulations, that pet food labels be registered and approved. Pet food labels must provide truthful and non-misleading information, as well as:
Clearly identify the product as a dog or cat food.
Display the quantity indication and the name of the manufacturer or distributor.
Display a brand name that does not mislead about its content or nutritional properties.
Provide a guaranteed chemical analysis in accordance with current animal feed laws.
List the ingredients in descending order of predominance by weight in the product.
A pet food may not make or imply any claim that a product is complete, perfect, scientific, balanced, etc:
It is nutritionally adequate for a normal animal at all stages of its life (growth, adult maintenance and gestation/lactation), or
The claim is modified by stating that it is complete and/or balanced for one or more specific stages of life.
Pet food ingredients
Pet food manufacturers use a wide range of agricultural ingredients. These products include meat, poultry, seafood and feed grains as well as products manufactured during the processing of food for human consumption. Ingredients are carefully selected based on their nutritional profile and functional contribution to the manufacture of products that provide complete nutrition for our pets.
Vitamins, minerals and preservatives are added as needed to ensure that products provide total nutrition and remain healthy during distribution and storage. Approved preservatives are used as a safety measure in commercially prepared pet food to help prevent deterioration, which could have adverse effects on the health of domestic animals.
Although the majority of ingredients used in pet food come from the United States, the domestic supply of ingredients cannot always meet the need for pet food production, which is available year-round so that products are available without interruption. Some ingredients are sourced from outside the United States based on seasonal availability, while others are only available overseas, such as certain ingredients essential to the production of a complete and balanced pet food such as certain vitamins, amino acids, minerals and micronutrients. It is interesting to note that the only significant intake of vitamin C in the world, which is taken as a daily supplement by people around the world, is China. Regardless of the country of origin of the ingredients, pet food manufacturers take great care to ensure the quality and safety of all the ingredients they use, regardless of their origin.
Eat high off the coast of the pig
You may have heard the saying: “Eat high on a pig”. The Americans have gotten used to doing exactly that. Yet how many of you understand the meaning of this saying nowadays? It is the habit of eating what many consider to be prime cuts of meat, i.e., those high on an animal’s body (e.g., shoulders, hams, steaks, roasts and ribs). This trend is different from the past, when it was said that many Americans ate all parts of the pork except the squealing.
In recent decades, most Americans have become very demanding about what exactly they will eat from animals raised for human consumption. Parts that are nutritious and which, not so long ago, were considered delicious, are now largely avoided. The list includes livers, kidneys, sweetbreads, tripe, chitterlings and feet.
In many parts of the world, these parts of the animal are still considered delicacies, as illustrated by the list of recipes on the right. In the United States, we often talk about these nutrients that we choose not to consume as by-products. In fact, we prefer by-products of steaks, chicken breasts and hams.
Animal co-products are important sources of protein, vitamins, minerals and amino acids and good quality essential fatty acids for pet food that do not affect the human food supply.
In fact, cats must have animal protein or chemically synthesized taurine and arachadonic acid added to their diet as a preventive measure against eye and heart disease, as they cannot produce these substances in their bodies by metabolism.
In the case of food crops, plant by-products are also used in the manufacture of pet food.
No filling, just a function
Making a complete and balanced pet food that provides all the nutrition a cat or dog needs is a complex task. Veterinarians have identified between 42 and 48 essential nutrients for cats and dogs. Ensuring that a pet food product provides the required nutrition means that three to four dozen ingredients are used regularly. In addition to the complexity of the ingredients, there is also the formal process by which these materials are defined.
For 100 years, ingredients used in animal feed, including pet food, have been defined by the Association of American Feed Control Officials (AAFCO). AAFCO has developed very specific ingredient definitions that pet food manufacturers must use on their product labels. In addition to describing the source of an ingredient (e.g., beef), these definitions often describe how the ingredient was processed (e.g., boned, ground and pasteurized).
Manufacturers of pet food must use the name of the ingredient AAFCO on product labels. The result is uniform ingredient labelling requirements across the country and, in many cases, around the world. It is because of the AAFCO ingredient definition process that the list of pet food ingredients includes component names such as wheat gluten, poultry by-product flour and sodium selenite.
Pet food ingredients – including those with strange names – all have at least one specific function in a product, whether to add nutrients, texture, maintain shape, preserve freshness or act in another way. Many ingredients perform multiple functions.
For example, wheat gluten is a relatively expensive ingredient that is used as a binder in pet food, just like the breadcrumbs on meatloaf. Without wheat gluten, canned products that contain slices, pieces or flakes would not retain their shape. Wheat gluten has the added advantage of being a source of quality and highly digestible protein.
Often, ingredients with funny and chemical names are sources of vitamins, minerals or essential amino acids. Many vitamins, minerals and amino acids are difficult for the body to process in a pure state and must therefore be included in food in the form of compounds. Some essential nutrients, such as potassium, are even deadly in their purest form.
Here are some examples of vitamin and mineral sources:
Sodium selenite – Selenium
Pyridoxine hydrochloride – Vitamin B6
Biotin – Vitamin B7
Menadione sodium bisulfite complex – Vitamin K (potassium)
Manganese oxide – Source of manganese
The reason why labels list sources of vitamins and minerals in this way goes back to the ingredient definition process. Regulations require that real chemical names appear on labels.