June 5, 2014


Author: Nancy Rawson

As an AFB International researcher, my goal is to learn as much as I can about what our pets like to eat and why. So each spring, my colleagues and I look forward to the Association for Chemoreception Sciences (AChemS) annual meeting where academics, researchers and industry types like us gather to learn what’s new in the world of chemoreception—gustation (taste), olfaction (smell) and trigeminal (face and mouth) sensation—for domestic and wild animals, as well as humans.

As a longstanding AChemS member, I had the opportunity to co-organize and facilitate a symposium at the association’s 2014 meeting in Bonita Springs, Fla., USA, which drew more than 200 attendees. The topic: Behavioral insights into food selection and flavor preference in domestic and wild animals.

Wild Thinking Encouraged
My AFB colleague Susan Jojola and I assembled a panel of four distinguished scientists who shared research on the behavioral cues of wild animals we thought might expand our knowledge of other mammals, including cats and dogs.

Here’s a sampling of what we heard and learned:

It’s that simple: Matthias Laska from Linkӧping University in Sweden compared how carnivores, such as Siberian tigers and wild dogs, on three continents responded to mammalian blood odor and a single blood odor component. He found in all cases the single component was as efficient as real blood in eliciting behavioral responses in these predator mammals.

In animal research, we tend to think of the factors affecting palatability as incredibly complex. However, as Dr. Laska showed, sometimes it comes down to one key element.

Sweet insights: Peihua Jiang from the Monell Chemical Senses Center in Philadelphia showed that the giant panda, which eats primarily bamboo—a plant very low in simple sugars—has a marked preference for compounds that taste sweet to humans.

This finding begs the question: If the panda, which doesn’t usually eat sweet foods, has not evolved to lose its “sweet tooth,” why did obligate carnivores like cats, who also don’t eat sweet foods, lose theirs?

Environment matters: Fred Provenza, retired from Utah State University, examined how dietary diversity maximizes nutritional health and flavor perception in wild and domestic animals. He showed that foraging herbivores like sheep make complex decisions on where to forage, what combinations of foods to eat and in what order to eat them based on an integration of wide-ranging influences that span generations, and change daily based on nutritional needs, available food and more.

Dr. Provenza’s work underscores the linkage between animals and their environment—for example, how the availability of diverse foods can reduce the amount eaten while improving health. This made us wonder: For companion animals, in addition to food diversity, how might environment influence palatability?

Understanding consequences: Bruce Kimball from the USDA National Wildlife Research Center in Fort Collins, Colo., and affiliated with the Monell Chemical Senses Center, showed that human-wildlife conflicts over resources can be better managed if we understand how positive and negative consequences impact the palatability of wildlife’s chosen food sources.

An important element of this research is paying attention to how animals interact with flavor stimuli. For example, understanding how skunks pick up bait and move it in their mouths helped the USDA create a bait casing for a vaccine packet skunks would chew on, but not eat. It’s the same concept behind cat or dog treat toys that provide just enough reinforcement to keep the animal entertained without them destroying the toy or losing interest quickly.

Making Connections
As Susan and I and our AFB research teams design research studies to learn more about companion animals, we’ll keep in mind key takeaways from this symposium, including the importance of:

• Tailoring study methods to various species
• Comparing cross-species behaviors to understand evolutionary and ecological drivers of flavor preference
• Considering the health and nutritional history of animals and the environments in which they feed

If you have comments, insights or questions of your own, we welcome them! Share them here or contact me at nrawson@afbinternational.com.


Tags: wildlife, wild animals, pets, food selection, flavor preference, environment, dogs, companion animals, chemosensory research, cats,


Please enter the word you see in the image below:

Nancy Rawson - May 5, 2015 - 11:31 am

Thanks for your comment Joe! Whether shifts in the taste receptor genes drove shifts in dietary habits or vice-versa is a fascinating topic. Add into the mix the intriguing discovery presented at AChemS that hummingbirds, which consume solely nectar, lack a T1R2 but are clearly sweet-preferring, and the T1R1/R3 is responsible for detecting both sugars and amino acids (Baldwin et al)! Considering the growing recognition of the roles for T1R2 in metabolism elsewhere in the body, we must also consider what alternative strategies the animals such as felines are using for those functions, when carbohydrates are included in their diets. The presentation at our symposium by Fred Provenza emphasized the importance of the environment on the organism, and discussed how preferences in sheep shifted in response to environmental changes. Whether a shift also occurred in taste or olfactory receptor profiles is not known. Thanks again for your interest – happy to communicate further on this or other topics!

Joe Brand - April 14, 2015 - 9:44 am

We demonstrated that the Tas1r2 gene in all Felidae is a pseudo-gene and that its product, T1R2 is not made. Together with Peihua Jiang in Bob Margolskee’s laboratory, we reported that certain other Carnovra have lost either the products of the genes, Tas1r1 or Tas1r2 and that the position of these losses on the genes were all independent of each other. The fact that these breaks in the genes occur at different places suggests that this strategy of pseudo-genization is not unusual and begs the question as to whether the loss of these genes triggered a change in food habits. Perhaps the panda lacks preference for sweet but retains the Tas1r2 because it requires this product for carbohydrate recognition purposes during digestion. The panda’s diet is not rich in any macronutrient, and the recognition of glucose and other simple carbohydrates becomes very important.