Kibble Size (Diameter) and its Impact on Feline Palatability

SCIENCE & TECHNOLOGY, AFB INTERNATIONAL

OVERVIEW
Creating a product that satisfies a cat’s preference can be challenging. Cats are obligate carnivores, which means they prefer higher protein diets over lower protein diets. They are more sensitive to spoiled food smells compared to dogs. The acidity of food can impact a cat’s salivation. The texture of food also affects the acceptance of the food. Different breeds of cats have various ways of picking up their food with their tongue. Cats use their canines, premolars, carnassials, and molars, but they lack lateral jaw movement, making texture and size crucial factors in their food preference.

Researchers at AFB International wanted to determine if kibble size (diameter) also affects the palatability of dry cat foods. This feline palatability research was a continuation of the previous work conducted around kibble shape. These results can provide both operations and product implications for pet food manufacturers.

EXPERIMENTAL DESIGN
In previous research, AFB found that the “disc” was the most palatable shape when tested versus multiple other shapes (star, triangle, cylinder, and triangle-hole). In this study, the size of the disc was evaluated with all possible variables being controlled – material, equipment, measurement methodology, and one lot of kibble meal used to make all three diameters.

The meal was a grain-based, 34/13 (Protein/Fat) diet, ground through a #3 screen. An ExtruTech 575 was used to manufacture the finished kibble. All the diameters had the exact specifications for moisture and bulk density. All diameters were coated with the same lot and amount [5.0%] of poultry fat and with the same lot and amount (1.5%) of a premium dry cat palatability enhancer.

ANALYTICAL TESTING

For this test, 3 different probes were selected:
TA-94: To evaluate how the kibble would react if the kibble was “crushed” by the entire carnassial/molar.

Texture – Crushed by Carnassial/Molar (TA-94)

TA-52: To evaluate how the kibble would react if split by the canine(s).

Texture – Split by Canines (TA-52)

TA-43: To evaluate how the kibble would react if split by the edge of the carnassial/molar(s). (used to evaluate hard kibbles for crunchiness)

Texture – Split by Carnassial/Molar (TA-43)

PERFORMANCE AND PAIRED PREFERENCE
For palatability testing, feeding trials were completed at AFB International’s Palatability Assessment Resource Center (PARC) with the same panel of 40 cats. Testing consisted of the two-bowl method paired comparison over two days. Each kibble diameter was tested against one another.

INTAKE RATIO                                  ACCEPTANCE TESTING

   

BEHAVIOR TESTING
1st Sniffing bout:
• Monadic: The duration spent sniffing the food first approached before tasting the food or being distracted.
• Paired: The duration spent sniffing the food first approached before choosing to explore the other food or losing interest in both foods.

1st Eating bout:
• Monadic: The duration a food’s flavor holds the cat’s initial focus before distractions become more interesting.Paired: The duration a food’s flavor holds the cat’s initial focus before exploring the other option by taste or smell.

Fewer Rejections:
The food with fewer occurrences where cats sniffed or licked a food and did not eat the food.

Enjoyment:
• Food focus relative to the time food is available (for wet food, includes Uptake and Savoring).

Leaves Less:
• The food that had fewer occurrences of cats turning away from the food.
Negative responses:
• Total recoils, headshakes, dropping food, tongue protrusions, mouth gapes.

CONCLUSION
After conducting analytical tests for performance and behavior, we found that as the diameter of the kibble increased, both its crunchiness and hardness increased when tested on a Carnassial/Molar model. However, in paired preference or consumption tests, cats did not show a statistical preference for the larger kibble. When considering attraction, sustained interest, and handling, cats did tend to choose the larger kibble.

To learn more about this topic or to speak with our Science & Technology experts, please contact your AFB Sales representative or afbinternational.com/contact.

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