By-products are what left after processing human food, this includes organ meats like liver and the kidney, by-products are a common ingredient in dry food.
These by-products while not used in the U.S. human food chain, they can provide important nutritional benefits.
by-products are rendered before use to remove moisture, kill bacteria and separate protein from fat.
How does the rendering process work?
Rendering usually evolves heat to turn raw material into stable, usable materials. Chemical and physical transformations are applied to remove moisture and to separate the fat from the bone and protein, the yield can be tallow, meat and bone meal, poultry by-product meal, etc…
The application of heat (240º to 290ºF) removes moisture but more importantly, it kills bacteria, viruses, protozoa, and parasites. excess cooking or high temperature may lower the nutritional value or digestibility of the final product, thus it is avoided.
Raw materials used in the rendering process are heavily loaded with microorganisms, research shows how effective the rendering process can be in killing microorganisms.
The by products used in pet food
Approximately 49 percent of the live weight of a cow and 44 percent of the live weight of a pig is not consumed by Americans.
When slaughtering and processing human-food, certain animal parts and meat that doesn’t meet certain aesthetics standard is rejected for human use will be used in animal feed, these parts may also include internal organs that are a big part of human-food in other cultures.
Carcasses of dead animals that died by means other than slaughter may be used indirectly in animal feed, these carcasses should be heat-treated and further processed, and shouldn’t contain any chemical additives. The final product should be free of potential microorganisms to control the risk of disease.
by-products may also include catering waste.
Nutritional benefits of by-products.
One of the final products of the rendering process is a vital feed ingredient in pet diets, it provides protein, essential amino acids, fat, essential fatty acids, minerals, and vitamins. These rendered ingredients provide more phosphorus, energy, iron, and zinc than other plant-based proteins.
These by-products are what left after the desirable parts for Americans are removed, hence the name “by-products”, some of these by-products are a major part of human diets in other cultures.
Some companies may list these by-products by name (kidney, liver…) and advertise them as “by-products free” to avoid the stigma that comes with the term “by-products”.
Safety of by-products
The organic materials used in the rendering process are filled with pathogenic microorganisms for humans and animals, rendering can be a safe way to handle these materials. it’s also known that the handling of the materials after the cooking process can be responsible for the contamination.
There’s strict regulation on what can be used in animal by-products, animal by-products exclude hair, horns, teeth and hoofs. And according to the AAFCO:
Based on nutrient content and safety resulting from processes used to produce the byproducts and the animal foods in which they are used, AAFCO’s position is that byproducts can be safely used to provide nutrition for lots of animals.
There have been many occasions of pet food recalls due to Pentobarbital contamination, Veterinarians use Pentobarbital as an anesthetizing agent and as a euthanasia agent. pets who consumed this drug over a long period of time will develop a tolerance to it, requiring even more dosage.
In the 90s reports from veterinarians to the FDA’s Center for Veterinary Medicine, claimed that some of their pet patients seem to be less responsive to the drug. They worried that pets might develop tolerance from exposure to the drug from pet food.
Reacting to these claims, the FDA launched two investigations to determine if pentobarbital residues were present in animal feed and if present, what risk does it pose to pets.
As I mentioned earlier, veterinarians use pentobarbital as a euthanasia agent, finding pentobarbital in pet food could mean rendered remains of dogs and cats are used in dog food.
As a part of 2 surveys one in 1998 and 2000, scientists analyzed dry dog food bought from retail outlets, they found pentobarbital contamination in some samples. As a part of their investigation, the FDA wanted if dogs and cats remains are used in pet food.
All samples that tested positive in the 2000 survey for Pentobarbital showed no signs of material that would’ve been derived from remains of dogs and cats, It’s assumed that the Pentobarbital in pet food is from euthanized cattle or hoses.
After Pentobarbital residue was found in dog food, the FDA wanted to know how much risks does it pose to dogs, to accomplish this, dogs were given specific quantities of Pentobarbital for 8 weeks, the scientist wanted to know how much Pentobarbital do dogs have to be exposed to that would show biological changes.
The research shows that dogs have to be exposed to more than 50 micrograms of pentobarbital per day to show any biological response, and based on the survey of dog food, dogs would be exposed to no more than 4 micrograms/kilogram body weight in a day, this assumption is based on the assumption that small dogs would eat dog food that contains the greatest amount of pentobarbital.
So to get to 50 micrograms per day needed to pose any risk, a dog would have to consume between 5 to 10 micrograms of pentobarbital per kilogram of body weight. but as we’ve mentioned earlier, the most that a dog would consume is 4 micrograms per kilogram of body weight in a day.
This led the FDA to conclude that exposure to Pentobarbital in dog food is very unlikely to cause any bad health effects.
You can read the full FDA report here.
There have been many occasions when the FDA or the food manufacturers ordered a food recall because of Pentobarbital contamination, you can read more about a brief history of Pentobarbital contamination cases here.
What do you think about by-products ?
Are you okay with by-products in your dog food? or do you avoid by-products? what do you feed your dog instead? Let me know in the comments below.