Through their diet, dogs ingest the energy required to perform and maintain all the functions of their organism. Therefore, depending on the quality of the nutrients present in their diet, they will have more or less energy and their organic system can perform the necessary functions with greater or lesser effectiveness. Energy is measured in kilocalories (kcal), equivalent to one thousand calories. It is gained mainly through the metabolisation of carbohydrates, proteins and fats. We should bear in mind, though, that part of the energy ingested will be lost during the digestion process. If, on top of this, we subtract the energy lost in faeces, we’ll get the amount of digestible energy. And if we also subtract the amount eliminated through urine, we’ll end up with the rate of metabolisable energy. There is a fourth factor involved in the amount ingested, which is the energy lost while generating heat. If ingested gross energy is subtracted from the energy used in these four factors, we’ll find out the net energy index that dogs have in order to perform metabolic processes, maintain the functions of the organism, perform motor activities, etc.
But we should also take into account another factor that is key in determining the biological value of the diet: digestibility.
The higher the digestibility index of dry food, the easier it is to digest and assimilate and the more it can be used by the organism.
The lower the degree of digestibility, the bulkier and more liquid the stools and the greater the frequency that the dog defecates.
Digestibility is directly related to the quality of the products used to make dry food: the higher the quality, the greater the degree of digestibility. For example, proteins are made up of amino acids, ten of which are essential, i.e. they have to be ingested through the diet because the dog’s organism cannot synthesise them by itself. If the proteins of animal origin used come from high-quality products such as the muscle tissue of beef, chicken, eggs or fish, the food will contain the essential amino acids required. However, if the protein source comes from by-products, not only will it fail to contain the essential amino acids, but it will also significantly decrease the digestibility index of the food.
A prolonged shortage in the intake of essential amino acids can trigger numerous problems in dogs, including anaemia, weight loss, increased blood sugar levels, coordination problems, dermatitis and behavioural problems such as irritability.
That’s why we must ensure that we feed our furry friends with dry food made from the highest-quality products that guarantee:
- a balanced diet rich in all the nutrients required to provide the metabolisable energy necessary for the proper performance of all bodily functions.
- the maximum degree of digestibility.
These two factors depend directly on the biological value of the proteins used in producing the food. However, the biological value does not depend on the percentage amount of the proteins, but on the ability of these to decompose in the amino acids that compose them. As a result, there are foods that contain a high percentage of proteins but have a low biological value because they have little capacity to split individually into the amino acids that compose them. This means that digestibility decreases and, therefore, there is less absorption of the nutrients. Consequently, there’s an increase in the frequency of defecation and the volume of the faeces, meaning that the dog will have less net energy for the functions that its organism requires.