This is an analytical (laboratory) term. Denotes the total amount of inorganic components; minerals (calcium, phosphorus, magnesium, iron, etc.) remaining after burning a food sample in an oven at 600°C (where all proteins, fats and carbohydrates are burned) [1]. The amount of ash in food depends on the mineral content, e.g. a high content of bone meal may increase it.
What it contains: The main sources of ash in the diet are bones (calcium, phosphorus, magnesium) and mineral supplements (e.g. from bone meal, fish meal or egg shells) [2].
Deficiency: Low ash levels simply mean low mineral content in the diet, which may result in general deficiencies, including: calcium, phosphorus or magnesium [3].
Excess: Too high ash levels (often in poor foods containing a lot of ground, meatless bones) hinder digestion and may burden the urinary system, predisposing to the formation of urinary stones, especially in cats [1] [2]. If the food has too high ash content with an excess of a particular mineral, symptoms of excess of that element may occur.
Sources
- Merck Veterinary Manual. Nutritional Requirements of Small Animals. https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
- Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ (2010). Small Animal Clinical Nutrition, 5th Edition. https://www.markmorrisinstitute.org/sacn5.html
- National Research Council (2006). Nutrient Requirements of Dogs and Cats. National Academies Press. https://nap.nationalacademies.org/catalog/10668/nutrient-requirements-of-dogs-and-cats