The role of protein in dogs

Protein is an important nutrient. It not only ensures the normal work of muscle tissue and the immune system, but also contains collagen and enzymes that promote body metabolism. Protein It is also a carrier in the blood and participates in the acid base balance of the body. ​​
Protein is composed of 22 kinds of amino acids. The dog's body can synthesize 12 of them, and the other 10 amino acids cannot be synthesized or cannot be synthesized in time to meet the needs, so they must rely on dietary supplements. Therefore, providing enough protein is a guarantee that the dog gets all the essential amino acids.
The nutritional value of protein is determined by its amino acid composition and its digestibility, absorption and utilization. The body's use of amino acids for protein synthesis is primarily limited by the amount of available amino acids. Amino acid availability means all amino acids are in the right ratio at the right time. In other words, at the wrong time or in the wrong ratio, these amino acids cannot be used to synthesize protein. When food fails to provide available amino acids, the body has to resort to protein from its own tissues to help.

Main sources of protein

Offal, lean meat, eggs and soybeans are all high-quality protein sources, because all amino acids in these four types of protein are in the appropriate ratio (can be directly consumed used to synthesize proteins). However, the first three animal proteins are easier to digest and absorb than soy plant protein. The biotransformation rate of animal protein is higher than that of ordinary plant protein because the amino acid ratio in animal protein is appropriate.

How much protein is appropriate for dogs to supplement every day?

After understanding the above simple knowledge, here comes the question that everyone is most concerned about! How much protein does my dog ​​need to eat every day? If you are feeding dog food, you might as well check the crude protein content on the dog food package first. ​​
The dog feed standards formulated by AAFCO require the crude protein content (dry weight) in the feed to be: 18% for adult dog feed, and 22% for puppy and breeding dog feed. ​​
The 18% and 22% refer to the content of crude protein. How are they related to the high-quality animal protein and plant protein mentioned earlier? Research shows that if dogs are fed high-quality animal protein, adult dogs only need 4-7% protein in their diet in terms of metabolizable energy. If you are feeding ordinary plant protein, adult dogs need 20% protein in their diet. Puppies and dogs during the breeding period require a relatively high protein intake. (Calculated in terms of metabolizable energy ME, 1 gram of protein provides 3.5 kcal.) ​​
Dogs are living creatures and they need to obtain energy from their diet every day.Taking protein, their bodies are breaking down and synthesizing protein every moment, so the protein in the body is dynamic. When a dog consumes insufficient energy, such as from carbohydrates, the dog breaks down proteins in its own body tissues and converts them into energy. Some diseases can cause a significant loss of protein in a dog's body more than starvation. (Therefore, for a considerable number of sick dogs, it is very necessary to eat high-carbohydrate liquid foods such as easily digestible rice cereal and porridge, because this type of food can quickly provide energy and reduce the massive loss of the sick dogs' own protein.)

Appendix 1: Calculation of daily protein reference value based on body weight

For each dog, the daily protein requirement is calculated as follows:

Minimum requirement: 2.5g*kg body weight^0.75

Normal needs for adult dogs: 5.0g*kg body weight^0.75

Puppies, pregnant nursing dogs and heavy-exercise working dogs: 6.5g* kg weight^0.75

Among them, weight^0.75 refers to the 0.75th power of body weight. Taking a dog weighing 10 kg as an example: the minimum daily protein requirement of this dog is: 2.5*10^0.75 = 2.5*5.6 = 14 gram.

If this is an adult dog with normal activity, its daily protein requirement is: 6.5*10^0.75 = 6.5*5.6 = 28 grams.

If this is a puppy, a pregnant nursing dog or a working dog with a high amount of exercise, its daily protein requirement is: 6.5*10^0.75 = 6.5*5.6 = 36 grams.

Appendix 2: Calculate the reference value of daily protein requirements based on the total amount of dry matter fed

The calculation method based on body weight seems a bit cumbersome. The simple calculation method is based on the total amount of daily feeding. That is, the daily food should contain 15-30% (dry weight DM) protein. If the water is removed from a dog's total daily feed, 15-30% of the dry matter weight is left as protein. Taking dog food as an example, the general moisture content is 10%, then 1000 grams of dog food is equivalent to 900 grams of dry matter. The protein content of this dog food should be 135-270 grams. If a dog eats 100 grams of dog food every day, it is equivalent to consuming 13.5-27 grams of protein. Vice versa, if a dog needs 1.5-27 grams of protein per day, eating 100 grams of this dog food is enough.