NRC Nutrient Requirements for Adult Dogs at Maintenance Explained

Click the Arrow to Access the Table of Contents Links • Guide Updated January 30, 2020

Understanding How to Use the Guidelines

The NRC nutrient guidelines for dogs provides a floor which is called minimal requirement (MR) or adequate intake (AI), a window, which is called recommended allowance (RA), and also, sometimes a ceiling, known as, safe upper limit (SUL).

These guidelines were established based on the findings of focused studies about dogs and it is a report organized into 15 chapters addressing nutrition aspects of dogs and cats and provides requirements tables and feed ingredients information.

The reason there is a floor, a window, and sometimes a ceiling, is because there is a range of nutrient levels that are safe to work within.

The Nutrient Requirements Data for Dogs is Sectioned into Tables of Four Categories

Click or press each tab to view the category & description

Minimal Requirements (MR): The minimal concentration of a bioavailable nutrient that will support a specific physiological state.

Defined as the concentration of a nutrient that is presumed to sustain a given life stage when no MR has been demonstrated.

The NRC goes on to further describe the process for establishing AI numbers which is based on “published data demonstrating the adequacy of a concentration or amount of a nutrient for a given life stage in the target species, which is supported, in some cases, by comparative data from studies in other species.”

The RA is the concentration of a nutrient in a diet formulated to support a specific physiological state.

The RA is based on the MR and, where applicable, includes a safety factor for nutrients with uncertain bioavailability. If no MR is available, the RA is based on the AI.

The SUL values are based on the maximum concentration of a nutrient that has not been associated with adverse effects in dogs.

Important Notes: SUL values aren’t available for a lot of the required nutrients which you will notice across the mineral and vitamin sections. This is why it’s important to feed at RA or appropriately above RA if a nutrient and its interactions allow for it to be above.

Dietary Nutrient Amounts

In order for dogs to obtain the correct amount of nutrients from the diet it is consuming, that diet must contain appropriate concentrations of each nutrient.

Because dogs eat to satisfy their energy requirements, one way to describe dietary nutrients amounts is units per 1,000 kcal of metabolizable energy. This is known in short-form as Amt/1,000 kcal ME.

Another way to express the amount of a nutrient in the diet, is as units per kilogram of diet. This is known in short-form as Amt/kg BW^0.75.

The Basis for Requirements of Adult Dogs at Maintenance Guidelines

The NRC canine nutrition guidelines for adult dogs at maintenance are based on a moderate sized lean 15 kg adult dog that consumes 1,000 kcal ME per day.

The maintenance energy requirements (MER) equations for adult dogs are based on data of dogs between 4 kg and 60 kg of mature weight.

*As discussed in the caloric feeding guide, MER is expressed as kcal of ME per kg of BW^0.75 per day.

*Important Note: MER expressed as kcal of ME per kg of BW^0.75 per day, is not the same as calculating nutrient needs by BW. BW is used in part to establish energy needs. Energy needs and nutrient needs are different. 

Additional Important Note: Calories are not a linear function of body weight. So variables do factor into the MER of a dog. This is why we do not calculate a dog’s nutrient needs by body weight (BW). Body weight is used as one of the components of calculating their MER and their individual MER is used to determine their nutrient requirements per ME.

The Requirements Relative to ME in the Food Compared with Requirements Relative to BW

Some requirements vary directly with BW & with various exponents.

The NRC published that studies have suggested “endogenous nitrogen output and, by inference, protein requirements vary with an exponent of approximately 0.75. Dogs reported endogenous nitrogen output to be 273 mg • kg BW^0.75, which suggests a MR of 1.7 g crude protein • kg BW^0.75.

Protein requirements expressed relative to ME in the diet should remain, therefore, almost constant irrespective of BW and are best expressed as relative to ME”

Note: Because we are discussing adult dogs at maintenance and not therapeutic diets, I won’t delve too deeply into the how and why attention should be paid to variations with BW when working with diets using MR or SUL. Adult dogs at maintenance are eating at the RA and we are not focused on the MR or the SUL in this guide beyond knowing their numbers for use as safety precautions.

Bioavailability Notes

Proposed minimal concentrations of vitamins are the total bioavailable forms of the vitamins present in the diet. This means by both natural ingredients and vitamin pre-mixes.

Because the natural forms of some vitamins have low bioavailabilities, the recommended amount will generally be adequate when the bulk of that vitamin is from a vitamin pre-mix.

“If a vitamin is contributed mainly by whole food ingredients, the minimal concentration needs to be modified to account for the bioavailability by using a suitable factor.” 

Article Sources

Nutrient Requirements of Dogs and Cats, NRC. (2006)

Bioavailability of Nutrients for Animals: Amino Acids, Minerals, Vitamins by Clarence Ammerman David Baker Austin Lewis. (1995)

 

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