Development of a preference ranking procedure with dogs

Abstract

Palatability of pet food is an important factor influencing food purchase decision of pet owners. In industry, single- or two-bowl methods are traditionally used to determine food acceptance or preference by pets but shortcomings exist to these methods. The first objective of this study was to propose and develop a preference ranking procedure. Preliminary testing consisted of five phases each lasting five days. Each day twelve beagles were presented 5 treats encased in identical rubber toys (“kongs”). The order of selection was considered as the ranking of preference. The five phases consisted of training, testing lab-baked treats formulations with five varieties of fats, starches and proteins, and commercial foods. The dogs generally ranked 1-2 flavors above others, indicating this procedure could be a more efficient method to determine preference since more samples can be evaluated simultaneously. The second objective was to validate this procedure by following the same process as the preliminary test. The results from phases 2 to 4 showed a similar pattern. For phase 5, various treat formulations were tested by combining the most to least preferred ingredients in each category. The results proved that the ranking of the formulations resembled the preference of the dogs for individual ingredients. Therefore, this procedure was concluded to be reliable. The third objective was to use descriptive sensory analysis to study the sensory characteristics of the treats and gain insights on the drivers of dogs’ preference. Five highly trained panelists profiled the aroma of the treats and the data was analyzed with the preference results collected from the dogs. The external preference maps showed that fish and meaty aromatics tended to be liked by the dogs and grain and musty/dusty aromatics appeared to be disliked. The last objective of this study was to further explore the applications of this procedure by studying the effect of toy/puzzle toy of the treat and ingredient dosage/ratio. With the same dogs, Styrofoam cups (puzzle toy alternative) and kongs were evaluated separately with the same treats. The results collected with Styrofoam cups were similar but less discriminating than kongs. It potentially suggested that the difficulty level of the toy can affect the significance of the dogs’ preferences. No significant preference was observed when testing the treats with different ratio of the most and the least preferred protein sources, although the human descriptive panel was able to provide different profiles for the samples. In conclusion, the preference ranking procedure is a reliable test method but more research is necessary to further explore applications.