Guide to nutrients

What you need to know about nutrients

A nutrient is a functional substance (usually of food) which sustains life. Ingredients supply nutrients; for example chicken is a good source of protein, niacin and selenium; which are all nutrients and can be utilized to good effect by the animal’s body.

The easiest way to differentiate between ingredients and nutrients is to remember that ingredients are tangible. These are the raw materials used to create a pet food recipe. Nutrients are intangible and can only be measured as a figure within the finished product. Fat can be a little confusing because it is both an ingredient and a nutrient. The chicken fat used in our products is a pure oil source and an ingredient, but the fat content of the  products is the sum total of all of the fats and oils in the product - of which krill, egg, meat etc all contributing to in addition to the chicken oil.

On pet food labels, ingredients are listed in descending order with that present at the highest level first within the “Composition” section. Nutrients are listed within the “Analytical Constituents” section and will always include protein, fat, ash and fibre.

Carbohydrates and moisture do not have to be declared. The Arden Grange dry foods contain 8% moisture. Carbohydrates can easily be calculated by subtracting the protein, fat/oil, ash, fibre and moisture percentages from 100.

Nutrients are declared on what is known as an “as fed” basis. Products with the same moisture content can be compared on this basis, but if you wanted to compare a wet food and a dry food, or dry foods with a different moisture content, you would need to convert the nutrient percentages to “dry matter”.

Example 1: Arden Grange Adult Chicken & Rice (25% protein as fed, 8% moisture)

1. Subtract the moisture content from 100 (100 – 8 = 92)

2. Divide the as fed protein percentage by your answer to 1. (25 divided by 92 = 0.27)

3. Multiply your answer to 2. by 100 (0.27 x 100 = 27)

The dry matter protein content of this product is 27%

Example 2Arden Grange Partners Chicken (11% protein as fed, 70% moisture)

1. Subtract the moisture content from 100 (100 – 70 = 30)

2. Divide the as fed protein percentage by your answer to 1 (11 divided by 30 = 0.37)

3. Multiply your answer to 2. by 100 (0.37 x 100 = 37)

The dry matter protein content of this product is 37%

This example illustrates how what may appear to be a lower protein diet purely on the basis of the label is not always the case. The same formula can be used to compare other nutrient levels too.


Protein is hugely important because its amino acid building blocks have many roles: structural (e.g. collagen and keratin), contractile (e.g. myosin) and transportational (e.g. haemoglobin). Protein is also needed for the manufacture of antibodies, enzymes and hormones. It is a less efficient energy source than fat and carbohydrate but can be used for this purpose if required. Dietary protein provides amino acids (e.g. lysine and methionine), which are vital since there are 10 of the 22 that the dog requires but cannot manufacture  enough of (essential amino acids), and 11 that the cat cannot manufacture sufficient levels of. Protein also provides nitrogen which is needed for amino acid synthesis.

Fat / oil

Fat provides a source of essential fatty acids (those which the animal cannot manufacture within the body, or cannot produce enough of); e.g. cats have a special requirement for arachidonic acid). Saturated fatty acids (triglycerides) are the primary source of energy for cats and dogs (1g of pure fat supplies 2.2 x more kilocalories than 1g of pure protein or carbohydrate, with 9 kcals/gram). Fat is used for insulation (e.g. around the myelinated nerve fibres), and structural and protective purposes (e.g. providing a cushion around the kidneys) and is a critical component of cell membranes. It is required for the absorption and transport of the fat soluble vitamins.

EPA and DHA are long-chain Omega-3 fatty acids which have many benefits due to their anti-inflammatory properties. They are important for the skin, heart, brain and eyes as well as many other organs and systems. They cannot be efficiently manufactured in the canine and feline body so a good dietary source such as the krill in the Arden Grange recipes is important.


Although cats and dogs do not require carbohydrate, simple sugars (monosaccharides) provide glucose and fructose for a readily available source of energy, and digestible sources (disaccharides and polysaccharides) provide starch; again for energy, and also helping maintain normal glucose homeostasis (in its stored form as glycogen). Consuming carbohydrate can have a protein sparing effect, which allows the animal to keep the protein for the important functions outlined above rather than utilising it as an energy source. In commercial dry dog and cat food, carbohydrates provide structure, texture, and form to kibble.

Many advocates of low carb diets for dogs and cats forget that ingredients primarily used as carbohydrate sources are actually also very useful sources of other nutrients. For example, maize is a good source of methionine and cysteine, niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), manganese, phosphorous and fibre.

While dogs and cats are not well-equipped to digest raw carbohydrate ingredients, in their ground and cooked form, many are very well utilised and serve a useful purpose.  

Carbohydrate also allows the manipulation of the protein and fat content of a food. For example, a dry diet with moderately low protein and fat percentages would have to have an increased carbohydrate content. This is because you cannot increase the ash, moisture or fibre levels beyond a small proportion, and all of the nutrients need to add up to 100%. Very high protein dry diets are very popular, but there is no benefit in loading a dry food with more protein than the animal needs because it cannot be stored. This provides more work for the body in de-animating and excreting it, which may explain why this type of food sometimes results in more waste/looser stools. This type of diet is also usually fairly high in fat, which can be disadvantageous for animals with a large appetite, tendency to unwanted weight gain or a sensitive digestion. Wet (and fresh) foods are different  because they are diluted with a lot more moisture.


Drinking water is the primary source of fluid, and it is the most vital nutrient. Approximately 70% of a lean adult animal’s body weight is water, and it is a crucial component of many tissues. It is needed for most metabolic processes and chemical reactions within the body. It helps absorb heat generated by metabolic reactions thus helping maintain stable body temperature. Temperature regulation is further aided by the ability of water to transport heat away from the organs via the blood. Digestion could not happen without it because it is needed for hydrolysis (breaking down large molecules into smaller ones) and it also provides the aqueous solution which facilitates action of the digestive enzymes. Water is needed for excretion too. Although the body can produce “metabolic water” (during oxidation of energy containing nutrients) this only accounts for a small proportion of fluid, so drinking is essential. Some moisture is present in food, particularly fresh or commercial wet food such as the Arden Grange Partners canned dog food. Arden Grange dry products can be soaked for animals who have a low fluid intake.


Fibre is a member of the carbohydrate family and there are two main types; soluble (usually fermentable, e.g. beta-glucans) and insoluble (usually non-fermentable, e.g. cellulose). Soluble fibre is used to produce short-chain fatty acids. It also delays gastric emptying and improves peristalsis (the muscular contractions that move food along the digestive tract). Insoluble fibre ensures an optimal transit time of food within the intestine, dilutes the colonic contents and binds to toxins. Fibre is derived exclusively from plant cell wall material.

Although cats and dogs do not have a specific requirement for fibre in their diet, a source in commercial complete cat and dog food which supplies a good balance of soluble and insoluble (e.g. beet pulp) is beneficial for the reasons above. Two functional fibre sources for cats and dogs are the prebiotics fructo-oligosaccharides (FOS) and mannan-oligosaccharides (MOS). They preferentially encourage the growth of the beneficial bacteria because pathogenic species such as Clostridia cannot readily use oligosaccharides as a substrate.

Both too much or too little fibre can have detrimental effects, with overly high levels resulting in excessive faecal and gaseous waste, and too little resulting in either constipation or diarrhoea depending on the individual animal’s requirements for this nutrient.


Minerals such as copper, zinc and selenium are inorganic chemical elements needed by the body. They have many functions and often work in conjunction with one another (e.g. the ratio between calcium and phosphorous is very important; especially for growing animals). Those with structural roles are generally required in larger quantities (macro-minerals such as calcium and phosphorous) than those with metabolic roles (micro-minerals/trace elements, e.g. magnesium).

Individual minerals do not need to be declared, but you will find the calcium and phosphorous percentages listed on the Arden Grange dry food labels due to their importance. Pet food labels do always include however a list of added minerals with a legal maximum or minimum (as opposed to those naturally present in many of the ingredients). One such example is zinc (as zinc chelate of amino acid hydrate).

Arden Grange use chelated minerals which are those that are bound to other molecules (typically amino acids) to improve their stability and ensure they are easily utilised within the body. This binding process does happen naturally during digestion, but it can be inefficient.

The total mineral content of a pet food is denoted by what is known as the ash content, which is a measurement of the non-combustible material in the food which is left after burning.


Vitamins are a diverse group of organic compounds needed for life with metabolic and functional roles. There are two types: water soluble (the vitamin B family including riboflavin, niacin and thiamine, and Vitamin C) and fat soluble (A, D, E & K).

Note about amino acids, vitamins, minerals & labelling

All Arden Grange products include all the amino acids, vitamins and minerals that dogs require at optimal levels. There is a lot more to the food than meets the eye because only the added vitamins and minerals with a legal maximum or minimum are declared. There are many more which are derived naturally from raw materials.