Feed grade ingredients, feed grade meat meal ingredients as example, are not required to be transported or warehoused under refrigeration. This lack of requirement for refrigeration is a selling point to pet food manufacturers, providing significant savings for cost to manufacture. But, at the same time the lack of refrigeration can be an issue of concern.
One issue of concern is rancidity. “Rancidity is a common problem in rendered animal products. It can have detrimental effects on both the quality and safety of the product. It is caused by the oxidation of fats and oils, leading to the formation of harmful compounds such as free radicals and hydroperoxides.”
Rancid pet food ingredients have short-term and long-term health effects on pets. From Eurofins laboratory: “rancid products can cause upset stomach leading to nausea, vomiting, or diarrhea. Longer term, free radicals are a concern. Free radicals, in layperson’s terms, are atoms that have unpaired electrons. These atoms look to find electrons to pair with and often damage key pieces of ours and our pets’ bodies such as proteins, DNA, cells, etc. In studies with humans, free radicals and oxidative stress have been linked to certain cancers, neurological disorders, and cardiovascular diseases such as heart disease.”
Due to the known risks of rancidity in commonly used pet food ingredients, testing for rancidity is important for manufacturers and ingredient suppliers. From Hanna laboratory instruments: “Rancidity or a poor peroxide value can strike during any step of the pet food production process (ingredients/materials, raw products, production, finished product/packaging). As fats, oils, proteins, etc., are exposed to the elements, they have small chemical reactions. These chemical reactions cause the oils and fats to oxidize. This affects the smell, taste, texture, and aesthetic of the finished products. Taking a whiff of pet food can be a bit stinky – but does the food smell stale or a bit off? It’s possible that rancidity may have started to set in. The more the pet food gets processed, the higher the risk for rancidity. For example, if the food is subjected to elevated temperatures during processing, that increased temperature can accelerate the rate that the food oxidizes.”
The pet food industry – including ingredient suppliers – perform peroxide value testing on ingredients to evaluate rancidity. “Peroxide value when tested typically gives you results in the amount of oxidation per kilogram of the fat/oil you are testing. Generally speaking, materials that have a value of 10 meq or below are considered fresh and good for usage. Anything that hits 30 meq and above, the product is generally considered rancid.”
But…the industry also tells us that rancidity testing (peroxide value testing) is often inaccurate. From PetFoodProcessing.net (bold added): “Very few discussions of analytical methods generate such passionate debates as the peroxide value (PV) test. This is a passion that many of the industry experts have in common. The best way to measure early markers of oxidation is a hotly debated subject. Today, every single industry applies its preferred methodology to measure PVs. Unfortunately, most of these different methods often produce different results. Some of these differences are small, while others can be quite large. This can result in conflicts between a pet food customer and an ingredient supplier. This hurts commercial relationships and costs the industry significant sums of money.”
Because of this admitted variation in testing results for rancidity, industry representatives are working together to develop a new method for testing for rancidity (peroxide levels). Those working to develop a new method to test for rancidity include representatives from Mars Petcare, Kemin Industries (ingredient supplier), Darling Ingredients (rendered ingredient supplier), Cargil (ingredient supplier and manufacturer), and Tyson (ingredient supplier).
The question is…should industry be responsible to develop their own laboratory analysis method when the results of the testing play such a significant role in animal health and in their profits? Industry admits the current testing variations “costs the industry significant sums of money”. Could they/would they develop a testing method that intentionally measures higher rancidity levels (peroxide values) as lower, allowing them to use more inferior quality ingredients?
Or are all concerned better protected if a new laboratory analysis method was developed by ONLY non-industry/independent scientists (whose livelihoods do not depend on the outcome)?
Personal opinion: Due to the importance of this particular testing method, independent parties should absolutely be involved.
We sent the FDA the following message:
The Center for Veterinary Medicine should be aware that members of the pet food industry have reported significant variations in testing methods for peroxide values of pet food/animal feed ingredients. Per the industry “Some of these differences are small, while others can be quite large.” Source: https://www.petfoodprocessing.net/articles/18722-inching-closer-toward-peroxide-value-measurement-standards
The industry has taken it upon themselves to develop another peroxide value method, with representatives of pet food manufacturing and ingredient suppliers involved. We are concerned about the outcome of this industry developed method and suggest to FDA to develop an agency suggested method that all industry would follow.
Pet owners deserve proper and consistent testing methods for pet food ingredient quality and safety. Unfortunately we cannot trust that an industry developed method would be in the best interests of pets, therefore we are asking the Center for Veterinary Medicine to involve themselves in this issue promptly.
Should we learn more from the FDA, it will be shared.
Wishing you and your pet(s) the best,
Susan Thixton
Pet Food Safety Advocate
Author Buyer Beware, Co-Author Dinner PAWsible
TruthaboutPetFood.com
Association for Truth in Pet Food
Become a member of our pet food consumer Association. Association for Truth in Pet Food is a a stakeholder organization representing the voice of pet food consumers at AAFCO and with FDA. Your membership helps representatives attend meetings and voice consumer concerns with regulatory authorities. Click Here to learn more.
What’s in Your Pet’s Food?
Is your dog or cat eating risk ingredients? Chinese imports? Petsumer Report tells the ‘rest of the story’ on over 5,000 cat foods, dog foods, and pet treats. 30 Day Satisfaction Guarantee. Click Here to preview Petsumer Report. www.PetsumerReport.com
Find Healthy Pet Foods in Your Area Click Here
The 2025 List
Susan’s List of trusted pet foods. Click Here to learn more.
The 2024/25 Treat List
Susan’s List of trusted pet treat manufacturers. Click Here to learn more.
Kathleen Phillips-Hellman
December 3, 2024 at 5:14 pm
Independent agencies should definitely be checking on the food that our pets are offered
T Allen
December 4, 2024 at 7:38 am
ROFL!! Industry regulating themselves? Only if there are laws telling them to and there are severe penalties for non-compliance. It’s hard enough to get human foods to pass inspection. And it’s going to be even worse the next 4 years! The PF industry would lose most of their production if rancid fats were not allowed. Why due you think cats turn up their noses at so much cat food? (And you shouldn’t try and force them to eat it!) Dogs are less concerned but I’ve had dogs refuse all kinds of food in the summer, and especially with kibble you can actually smell the rancid odor at times. Third party monitoring is the only way to address the issue. Or stop feeding commercial pet food.
kay
December 9, 2024 at 3:54 pm
It would not change anything. Commercial food is horrible. The best thing for any pet owner, is to get meat from the grocery store, better yet, a butcher meat market. Get a grinder, grind the meat yourself, using all safety measures. Fix individual freezer bags, cook the meat when ready to feed. I add fresh cooked carrots, fresh spinach, squash, pumpkin. I also use Chickpea powder or cooked Quinoa. Mix and match. I also do re search on a good protein Vitamin powder, also Dr Judy’s website has supplements. I wish more pet owners just would acknowledge, before getting a pet. Now, the feral cats outside, get kibble and some wet food, but they are not mine.