3. General Items about Cats
• As obligate carnivores, will choose higher protein diets over lower protein
diets.
• More likely than dogs to avoid spoilage aromas.
• Lack lateral jaw movement; hence, texture and size are very important.
• Lack molars, and cannot grind their food. Acidification helps salivation.
• Surface texture plays a role in palatability.
– Different breeds of cats pick up their food differently with their tongue.
• In PAL testing, cats tend to consume food from both bowls. First choice is
not necessarily linked to total consumption. Feeding time is generally 15
hours.
4. Factors Affecting Feline PAL
Raw Materials
(Fats, oils, meals, palatants, etc.)
Texture / Size / Processing
Shape
6. Experimental Design
• Standard / fixed reference points:
– A finely ground (#3) 34/13, grain-based meal
– Same lot of meal used for all shapes
– All variables coated with the same components
• Fat: 5.0% poultry fat
• Palatant: 1.5% dry cat palatant
– Same moisture specification: 6.5% - 9.5%
– Same density specification: 19 - 24 lbs./ft3
7. Experimental Design (cont’d)
• Variable(s) in the study:
– Kibble shapes
1) “X” Cross / Star
2) “∆” Triangle
3) “O” Flat Disc
4) Cylinder
5) Triangle w/ center hole
8. Experimental Design (cont’d)
• What was measured:
– Texture
a) Max. Load c) Energy to Break Pt.
b) Energy to Yield Pt. d) Toughness
– PAL due to kibble shape
a) 2 bowl, paired comparison test
b) 25 cats x 2 days
c) Same panel of cats was used
d) All possible paired tests were done (10)
13. Texture Analysis Terms
• Maximum Load – maximum amt. of force
necessary to “fracture” a kibble (measured in kgs
of force).
• Energy to Yield Point – energy required to reach
a point where kibble begins to fracture
(measured in gram•inch).
• Energy to Break Point – energy required to reach
a point where kibble finally gives way and
fractures completely (measured in gram•inch)
• Toughness – energy to break point divided by
gauge length * kibble width * kibble thickness
(measured in g/inch2)
14. Texture Analysis
Max. Load Energy to Yield Pt. Energy to Break Pt. Toughness
Shape
(kg-Force) (gram-inch) (gram-inch) (g/inch2)
“O” [Disc] 5.39 41.46 56.85 227.39
“X” [Cross] 8.08 51.39 69.06 276.23
“∆” [Triangle] 7.06 63.79 100.10 400.41
Triangle w/ hole 2.48 14.07 20.54 82.15
Cylinder 4.23 61.99 145.45 626.90
• Measurements done with an Instron Texture Analyzer
#3342 and Cherry Pitter Needle probe
19. Texture Summary
• The Triangle w/ hole had the lowest texture numbers.
• The Cylinder had the highest scores in all categories except
maximum load.
• The “O” [Disc] had the second lowest texture numbers.
• The “X” [Cross] scored in the middle except for max. load
where it had the highest number.
• The “∆” [Triangle] had the second highest scores.
20. PAL Data Interpretation
• Consumption Ratio (CR): Consumed A / Consumed B
• Intake Ratio (IR-A): Consumed A
(Consumed A + Consumed B)
• First Choice (FC-A): % Animals eating out of Bowl A first
• Preference: Outside the range of 0.45-0.55 IR
• p-Value (p): Probability that A is significantly different from B
(want < 0.05 = 95% confidence level)
25. Cylinder
Ration A Ration B IR-A CR FC-A PREF p-Value
“X” [Cross / Star] 0.37 1.7B 0.48 5A : 17B 0.000
“∆” [Triangle] 0.29 1.5B 0.59 3A : 12B 0.086
“O” [Disc] 0.36 1.9B 0.61 2A : 12B 0.002
Triangle w/ hole 0.39 1.6B 0.39 5A : 11B 0.028
Cylinder lost to the other (4)
shapes
26. Conclusions
• Kibble shape was the primary driver for PAL - texture
across a given range did not drive PAL.
– Triangle-hole had the lowest texture scores, but few cats preferred
this shape.
– The “O” [Disc] had mid-range texture scores and was the most
preferred shape.
– The Cylinder was outside the range and was least preferred.
– The “X” [Cross] had slightly more favorable texture scores than the
cylinder; however, its PAL was closer to the “O” [Disc]
– The “∆” [Triangle] had higher texture scores than the “O” [Disc] but
similar PAL
27. Product Considerations
• The “O” and the “X” had the best overall PAL
– Head-to-head, the “O” was better.
Operations Implications Product Implications
The “O” is easier to extrude The “O” is more durable
•Less potential for die blockage The “O” had less fines
•↓ drag = ↑ throughput The “O” has more surface area
The “O” has lower tooling costs
