Pet food manufacturers and dog owners know that the healthiest, most nutritious dog food in the world won’t do any good if the dog won’t eat it. So palatability plays a crucial role in the formulation of dog diets. But you can’t ask a dog “how did you like your dinner” or “would you prefer the beef or the chicken,” so how do you know? You test with feeding trials.
The traditional method has been the two-bowl feeding preference test. Pet food manufacturers either use their own kennels of dogs or hire outside testing companies. In the test, the dogs are offered two different foods in identical bowls. Each bowl contains more than the dog’s caloric requirement for the day, so that the dog will not consume both foods just to feel full. The foods are switched between the left-side and right-side positions to counteract any canine preferences for going to one side or the other. The food’s immediate appeal is assessed on its initial presentation, but the trial is continued for some weeks to determine the dog’s long-term interest in the food. (Some dogs are simply attracted by novelty, and will choose any new food over an accustomed diet, but then prefer the old diet once the novelty wears off.)
But there have always been acknowledged problems with the in-kennel two-bowl preference test. Kennel dogs may develop food habits, as they will generally be fed the diet manufactured by the company that owns the kennel. The lifestyle often doesn’t resemble the lifestyle of dogs living in individual homes. And the opportunity to overeat (because of the excess food provided) isn’t good for the dogs.
In an attempt to overcome these potential drawbacks, testing companies have developed more involved protocols. French testing company Panelis works to eliminate dogs with a strong left-right position bias from their panels by continuously considering the frequency of higher food intake on one side than the other. They also feed a wide diversity of different products to the dogs to try and avoid the formation of any feeding habits. And they use results from their testing panels in France, Brazil, and the United States to further diversify their results and eliminate potential bias. They can select down to individual dogs from the various panels.
Pet food ingredients supplier Kemin Nutrisurance has taken the two-bowl test out of the kennel and into the home. This strategy provides the immediate advantage of using dogs living in homes with owners, rather than kennel dogs. It also gains the owner’s perspective on the dog’s acceptance and enjoyment of the food (an important consideration for pet food manufacturers, as they understand that consumers will be more likely to continue purchasing a food that they believe their dog enjoys eating). The breeds of dogs can also be more diversified than the typical kennel, encompassing canines from toy to giant.
However, this is a difficult transition. A significant number of dog owners have to be recruited and trained to perform a standardized test. Owners have to be willing to minimize treats and snacks and to faithfully record a variety of observations. And of course the dogs have to be kept healthy throughout the testing.
To try and gain the benefits of in-home testing while avoiding the difficulties, AFB International opened a dedicated Palatability Assessment Resource Center (PARC). Both dogs and cats live at PARC. The dogs enjoy daily socialization, training sessions, grooming, and play both with individual humans and with other dogs. They are given both regular meals and treats. AFB believes that this not only more closely duplicates the actual in-home feeding environment, but allows them to see each dog’s personality and thus to better judge the dog’s level of enjoyment of a food.
Palatability testing in dogs is complex for all of these reasons and more. Canines can be either attracted to or phobic about novelty, so these factors have to be sorted out. And flavors are important to dogs, but other considerations also enter the picture. The size, texture, and even shape of a piece of food all combine into what is called “mouth feel,” and this can greatly impact a dog’s acceptance or rejection of a food.
In case you’ve ever wondered how palatable dog food might be to you, but haven’t worked up the nerve to actually give it a try, the American Association of Wine Enthusiasts (AAWE) has done it for you. In 2009, the AAWE held a blind tasting for human volunteers, with samples of spam, liverwurst, pork liver pate, duck liver mousse, and Newman’s Own dog food. Though the tasting panel was small (consisting of eighteen people), only three tasters correctly identified the dog food. That equates to only slightly over 16 percent, and could actually result statistically simply from guessing. The AAWE concluded that, in general, humans are not able to distinguish the flavor profile of organic dog food from other meat-based products meant for human consumption.
Next time – Mixed breeds at work