Written by: Zoe Russell BSc (Hons)
Graduate Nutrition Officer, Skinner’s Pet Foods
Sometimes food labels can be a minefield of nutrition terminology, making it difficult to know exactly what is inside your dog’s food. Therefore, to provide the best possible support for them, it’s important we know what’s going into our dog’s food, and why.
Crude ash is a measure of the inorganic substances present in a food product- also known as minerals. However, ash is a very mis-understood ingredient, as people often assume it’s added to “bulk” out the product- but in fact it is an extremely useful component in food as it’s made up of essential minerals including sulphur, phosphorus and sodium¹.
Where does Ash come from?
Ash is the residue from heated organic products including proteins, fats and carbohydrates. By heating these products, it isolates essential minerals which can be used in a dog’s food to support normal physiological function. The amount of ash in each type of food is however dependant on the ingredients, but it is normally between 5% and 8%.
When reading food labels, you will often see the ash content referred to as “crude ash”- this is simply an analytical term which refers to the total mineral content of the food. Although crude was once thought to mean “poor quality”, this is in fact a myth!
What Essential Minerals does Ash contain?
Ash contains many essential minerals including sulphur, which is an important nutrient for both humans and animals. Inside the body sulphur helps make up essential amino acids including cysteine and methionine, which form the “building blocks” of proteins. As proteins are vital for many cellular processes in the body, it is important we provide key minerals in our dog’s diet to help facilitate this².
Another important mineral found in ash is phosphorus. This is a highly abundant nutrient in the body which helps to make up important tissues, including teeth and bones³. As well as this, phosphorus supports metabolic function, and helps to form energy-carrying molecules in the body.
Finally, ash contains sodium- an element vital for controlling fluid balance outside the cells and facilitating the transmission of nerve impulses². However normal sodium levels must be maintained to ensure cardiovascular and muscular processes function correctly⁴.
Changing the Myth
Although ash is often a highly mis-understood ingredient, it contains essential minerals that are needed for every-day physiological functioning. In the case of our feeds it holds a very important role and will never be used as a “filler” or “bulk” ingredient. Instead it is a key component which helps support the health and well-being of our beloved pets.
(1) McDonald, P., Edwards, R., Greenhalgh, J., Morgan, C., Sinclair, L. and Wilkinson, R. (2011). Animal nutrition. 7th ed. Harlow, England: Pearson.
(2) Hine, R. (2015). A Dictionary of Biology. 7th ed. Oxford: Oxford University Press, pp.479-569.
(3) Heaney, R.P., Graeff-Armas L.A. (2018). Vitamin D Role in the Calcium and Phosphorus Economies. 4th ed. Academic Press, pp. 663-678.
(4) Scott, T. (2001). Taste, Neural Basis of. International Encyclopedia of the Social & Behavioral Sciences, pp.15447-15450.