Functions of fat

Functions of fat

Fats are one of the three macronutrients of an animal’s diet

Definition of fat

Fats are one of the three macronutrients of an animal’s diet, providing an energy source and supplying building blocks for the formation of tissues

Triglycerides are the primary form and are categorized according to the fatty acids they contain. Fatty acids are classified as saturated, unsaturated, or polyunsaturated according to their structure. All fatty acids share some common functions, including provision of energy, absorption of fat-soluble vitamins, and incorporation into cellular membranes. 

Essential fatty acids

There are two specific types of polyunsaturated fatty acids (PUFAs) that are considered essential. Omega 3 fatty acids and omega 6 fatty acids are named according to where the first carbon double bond is located within the carbon chain. These acids have important roles in cell membrane structure, neurologic development, immune function, and managing inflammation. Examples of omega 6 fatty acids include linoleic acid and arachidonic acid while examples of omega 3 acids include eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). Fatty acids are found in both oils and animal fats.

Types of oils

Fish oil and flax seed oil are commonly used as a source of omega fatty acids in pet foods. Generally, pet food companies add omega 3 fatty acids to their foods to lower the ratio of omega 6 to omega 3 fatty acids. Although the ratios may be a guideline, the actual concentration of EPA in the omega 3 is ultimately the most important. Research has been performed and determined that the optimal omega 6 to omega 3 ratio is between 10:1 to 5:1.

Types of animal fat

Chicken fat is the most commonly used type of fat in pet food. Pork fat is also used for pet food but may be less palatable. Products coated with pork fat tend to feel less greasy than those coated with chicken fat. Although palatable, beef fat is used the least due to challenges with (protein) beef free claims and its relatively high melting point which complicates practical application.

Fats for palatability

Besides providing an energy rich source, fat influences the willingness of animals to eat the food in preference to others. 

Fat contributes to the palatability of a formula by influencing aroma, flavour, and texture. However, a common perception is the more fat a product contains, the more palatable that product will be. The test presented above compares different fat concentrations in different palatability systems. Results indicated that an increased amount of fat on cat food does not necessarily improve palatability.

For dog food on the other hand there is evidence that a higher level of fat improves the palatability (see graph ‘Effect of fat application rate on palatability’).

Conclusion

Total palatability requires much more than adding a palatant and can be influenced by fat application. Here we have discussed the type and function of fats in pet food. Be on the look-out for more information on fats from AFB.