Crude Protein in Cat Food Meaning and Requirement

What is the crude protein in cat food

Crude protein in cat food refers to the amount of protein contained in that specific food based on a laboratory analysis of its chemical composition (not quality).

Usually, its nitrogen content is used as the basis calculating or estimating the amount of crude protein since it has amino acids which have nitrogen in them.

However, nitrogen can be affected by which amino acids are present. Additionally, this method of analysis may inflate the actual amounts of protein since not all nitrogen may be from amino acids i.e., the nitrogen could be from products such as melamine.

However, considering true protein quantity will give a more precise or actual amount in specific feline food since it obtained by directly measuring its level present.

Finally, all pet food labels are legally required to indicate the amount of crude protein (sometimes referred to as ‘protein’) as well as that of other ingredients including crude fiber, crude fats and so on.

Guaranteed Analysis (GA) and dry matter

A guaranteed analysis of a pet food label indicates nutrient level it as fed (not based on dry matter analysis) where the minimum amounts of protein, fat, minerals, vitamins, and so on, as well as the maximum fiber and moisture content, are provided.

From a guaranteed analysis, it is possible to see if a specific cat diet meets the minimum recommended nutritional level. Unfortunately, this will not indicate the quality of the nutrient.

GA is determined by laboratory analysis or computer software with a nutrient content database for all the nutrients used.

On the other hand, dry matter refers to pet food without any moisture in it. For instance, from the GA, you can determine its dry matter i.e., by deducting the amount of moisture.

Once you have the dry matter, it is easy to compute the various nutrient level and see if they meet the recommended amounts.

Crude protein in cat food
Crude protein in cat food

Dry matter nutrients computation

For instance, if we use the one for Purina Cat Chow, the GA is as follows:

Crude Protein (Min)32.0%
Crude Fat (Min)12.0%
Crude Fiber (Max)3.0%
Moisture (Max)12.0%
Linoleic Acid (Min) 1.25%
Arachidonic Acid (Min)0.03%
Calcium (Ca) (Min)1.1%
Phosphorus (P) (Min) 0.9%
Selenium (Se) (Min) 0.30 mg/kg
Vitamin A (Min)10,000 IU/kg
Vitamin E (Min)70 IU/kg
Taurine (Min) 0.15%

The dry matter will be 100 less maximum moisture content (100-12) = 88

To get dry matter percentage of any nutrient, you should divide the reported nutrient content by dry matter as a percentage.

For instance,  the minimum % of crude fat based on the dry matter is  (12/88) x100 = 13.64%

Finally, when doing your math, do not forget to factor in your cat’s weight, age, activities, how easy the source will be digested among many other factors.

Why do cats need protein?

  • They are a source of various amino acids used as protein building blocks that make the various body organs and tissues including tendons, cartilages, skin, hair, muscles and so on.
  • They work as hormones, antibodies, enzymes, and help in proper pH balance.
  • Together with fats, these two their primary source of energy.

How much crude protein should be in cat food?

From the above discussion, you should know that both the crude content and guaranteed analysis do not talk about the quality but rather the quantity of nutrients present.

According to AAFCO, based on dry matter, the minimum required crude protein by cats for growth and reproduction is 30.0% while for adult maintenance, it should be at least 26.0%.

Basing on 1000 kcal metabolizable energy (ME), the amounts will be 75g and 65g respectively. Therefore, the total amount will depend on the calorific consumption of your cat.

Although NRC’s requirements have slightly lower amounts of 50g/1000 kcal ME for adult maintenance and 56.3g/1000 kcal ME for reproduction and growth, the AAFCO uses these amounts to come up with the above recommendations and therefore they are related.

Senior cats tend to have kidney problems as well as sarcopenia. Formulating the right amount of protein needs to account for these two.

On average, an adult cat weighing about 9 pounds whose daily food consumption is 250 calories should be given 12.5g of crude proteins daily while kittens weighing 1.8 pounds require about 10g since they are growing.

Nursing cuts will require much higher amounts with one that has 4 kittens and weighs 9 pounds requiring a whopping 41g of crude proteins daily.

Also, expect some health problems if your cat does not get all the necessary amino acids, which include, arginine, histidine, isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, threonine, tryptophan, valine without forgetting taurine.

High-quality protein cat food

When selecting the right protein source, you need to bear in mind that unlike dogs, cats are strict carnivores whose ideal diets should be should mimic the raw diets they prey on.

According to Cornell University’s College of Veterinary Medicine, they “consume prey that contains high amounts of protein, moderate amounts of fat, and a minimal amount of carbohydrates.

Common sources include:

Natural sources

Some of the high-quality protein sources are from animals such as fish, meat (beef, pork), poultry and eggs since they are loaded with most of the required essential amino acids.

Also, if the animal and plant protein sources are correctly combined, they can help compliment the various essential amino acids required. However, some sources from plants may not be readily bioavailable and may lack some nutrients such as taurine.

Commercial diets

If you rely on commercial cat foods, the best high-quality protein foods include those have a high proportion from animal sources where real meats are the first ingredient.

Also, they should be wheat, grain, corn or soy-free or contain very little or properly mixed to ensure a healthy balance. Grains in moderation does help in holding the proteins together in dry foods as well as provide the fiber necessary for bowel movements.  Up to 10% carbs on a dry matter basis are ok.

Therefore, when choosing them, look at not only the specific protein content but also consider if it has other vital nutrients including fats, the essential amino acids, taurine, vitamins, and mineral as well as appetizing flavors.

Some good sources include

These are not the only brands in the market. There are many others. You need to look at expert reviews, what users are saying and their ingredients

Finally, there are scenarios where low protein food may be recommended such as in the case of renal failure. However, your vet needs to ensure they do not deplete lean body muscles.

See also

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