Ÿnsect’s new mealworm-based wet pet food ingredient, WetPro15, is nutritionally excellent, environmentally sound, and functionally transparent for pet food manufacturers. These attributes will appeal to pet owners who are seeking quality alternatives to conventional ingredients — but the bottom line is, how will our cats and dogs respond to it? Here, we report the results of two new studies that reveal that including WetPro15 in the diet has no negative effect on palatability for pets, and no detrimental effects on faecal consistency in dogs.
Insect protein is one of several novel protein sources that are raising interest among pet-owners who are seeking alternatives to conventional meat-based pet foods. This interest in alternatives is in part motivated by their perceived nutritional and environmental benefits. As recently reported in our previous article1, our ingredient, WetPro15, certainly meets these criteria: the mealworm pulp has a higher protein-to-fat ratio than proximate products such as MDMs; it is a natural source of linoleic and oleic acids; and its ileal and peptic digestibility are greater than 90%. From an environmental standpoint, its climate change contribution is equivalent to chicken MDM, and significantly lower than other meat-based protein sources.
However, while pet-owners are increasingly evaluating products based on their nutritional and environmental profile, there are other factors that contribute to their choice of their pets’ diet. One of these is how much enjoyment the pet derives from its food: a recent study has reported that palatability is the fourth-most important aspect of a pet food (out of fourteen attributes surveyed) that pet-owners consider when choosing their companions’ diet2 and it is moreover considered an aspect of animal welfare, coming under Provision 5 which mandates for “positive mental experiences”3. Palatability, which encompasses visual, olfactory and textural cues in addition to taste per se, appears to be particularly important for cats, which show greater selectivity than dogs4. It is therefore important that any novel ingredient should undergo palatability trials. Here, we report on a preliminary trial conducted by an external partner that reveals that incorporating WetPro15 into a poultry-based paté does not diminish the palatability of the food.
Another factor that is of particular concern to dog-owners is the digestibility of the food —specifically regarding how it affects the dogs’ faecal characteristics. We have previously reported results of a safety trial of our dry pet food ingredient, Protein70, which showed that dogs’ stool quality scored an ideal score of 3 – “moist and formed”5. Here, we report on a new trial in which we confirm similar results for WetPro15.
Palatability trial on cats
To evaluate the palatability of WetPro15, we carried out a two-bowl test in which 33 cats were offered a choice between a control paté, whose animal protein source was poultry MDM, and a test paté, in which 40% of the animal protein source was replaced with WetPro15. As shown in Figure 1, there was no significant difference in intake ratio (one-tailed t-test at 95% confidence), meaning the cats were as eager to consume the test diet as the control diet. Moreover, cats chose the test paté first 59% of the time, which indicates that visual and olfactory cues were positive.
Palatability and faecal consistency in dogs
Our dog trial was performed via a 10-day monadic test in which 32 adult dogs were either fed a control paté (poultry MDM 50%) for five days followed by a test paté (20% WetPro15 & 30% poultry MDM) for five days, or vice versa. As shown in Figure 2a, there was no significant difference in intake quantity – a total of 309 g of test paté (blue) was consumed, compared to 288 g of control paté — indicating that the insect protein was no deterrent to consumption.
The dog owners were asked to report on aspects related to the digestibility of the diet, including the firmness and quantity of the dogs’ faeces (figure 2b). The diet including WetPro15 was associated with “just right” faecal consistency by 81% of owners, compared to only 63% for the control diet. Moreover, 22% of owners reported increased flatulence after the control diet, compared to only 6% after the test diet.
When owners were also asked to judge their pets’ enjoyment of the food, 75% reported a high level of enjoyment from the test paté, compared to only 63% from the control paté. Overall, 28% of dogs were reported to prefer the test paté compared to only 13% preferring the control (Figure 2c); nearly 60% showed no preference.
Moving forward
While further studies are required to determine the significance of these observations, they certainly suggest that at the very least, the presence of WetPro15 was no deterrent to either cats or dogs, in terms of the palatability of the food and to dogs’ enjoyment of their food.
Besides, the canine trial suggests further that a diet including mealworm protein has digestive benefits for dogs. This is probably related to the presence of chitin in the mealworm pulp, which is known to be a good source of natural fiber.
The palatability of insect-based pet foods is perhaps unsurprising, in principle, considering that catching and consuming insects (among other prey) is a natural behaviour for both dogs and cats. In comparison to conventional wet pet food products, our WetPro15 has no obvious visual or olfactory deterrents: the mealworm pulp’s light brown colour makes it visually similar to traditional products, and it is not associated with any strong odour. Moreover, as previously reported in our article6, it is texturally similar to patés made from chicken MDM. Hence, from the perspective of the animal, including WetPro15 in the diet appears to be largely transparent: mealtime for them is “business as usual”.
These initial results are an encouraging indication for pet-owners that they can offer their companions a diet that is both nutritionally and environmentally superior, without sacrificing their tastebuds.