Page 14 - Small Animal Clinical Nutrition 5th Edition

An Iterative Process 15

VetBooks.ir Box 1-6. A Method for Calculating the Food Dosage Estimate.

Canine DER
Calculations to estimate food dosage are based on the assumption
that if a food contains the proper proportions of nutrients relative to Maintenance (1.0 to 1.8 x RER)
its energy density, and is fed to meet an animal’s energy require- Neutered adult = 1.6 x RER
= 1.8 x RER
Intact adult
ment, then the animal’s requirements for non-energy nutrients will Inactive/obese prone = 1.2-1.4 x RER
automatically be met. This calculation has three steps: Weight loss = 1.0 x RER
1) Estimate the energy requirement of the animal (Table 1). Critical care = 1.0 x RER
2) Determine the energy density of the food (kcal or kJ ME/g food, Weight gain = 1.2-1.8 x RER at ideal weight
as fed basis). Sources include product labels, product literature, Work
contacting the product’s customer service department by phone Light work = 1.6-2.0 x RER
or e-mail (phone numbers or e-mail addresses can often be Moderate work = 2.0-5.0 x RER
found on the product label). The energy density can be calculat- Heavy work = 5.0-11.0 x RER
ed using Atwater values (Tables 2 and 3). Gestation
3) Divide the energy requirement of the patient by the energy den- First 42 days: feed as an intact adult.
sity of the food to determine the daily amount to feed (food Last 21 days: use 3 x RER. (This quantity may need to be
dosage). increased to maintain normal body condition for some dogs, espe-
cially larger breeds.)

Table 1. Calculation of energy requirements. Lactation
Lactation is nutritionally demanding and the physiologic and nutri-
Calculation of daily energy requirement (DER) is based on the rest- tional equivalent of heavy work.
ing energy requirement (RER) for the animal modified by a factor to Recommend 4 to 8 x RER (depending on number of puppies nurs-
account for normal activity or production (e.g., growth, gestation, ing) or free-choice feeding.
lactation, work). RER is a function of metabolic body size. RER is The following table may also be used to estimate the DER of lac-
calculated by raising the animal’s body weight in kg to the 0.75 tating bitches:
power. The average RER for mammals is about 70 kcal/day/kg
metabolic body size: RER (kcal/day) = 70(BW kg ) 0.75 or 30(BW kg ) + Puppies (No.) DER
70 (if the animal weighs between 2 and 45 kg). RER values can 1 3.0 x RER
also be obtained from Table 5-2, Part 3. Expressed in kJ, the aver- 2 3.5 x RER
age RER for mammals is about 293(BW kg ) . These energy 3-4 4.0 x RER
0.75
requirements should be used as guidelines, starting points or esti- 5-6 5.0 x RER
mates of energy requirements for individual animals and not as 7-8 5.5 x RER
absolute requirements. 9 ≥6.0 x RER
Feline DER Growth
Maintenance (0.8 to 1.8 x RER) Daily energy intake for growing puppies should be 3 x RER from
Neutered adult = 1.2-1.4 x RER weaning until four months of age.
Intact adult = 1.4-1.6 x RER At four months of age energy intake should be reduced to 2 x RER
Inactive/obese prone = 1.0 x RER until the puppy reaches adult size.
Weight loss = 0.8 x RER
Senior adult (7-11 years) = 1.1-1.4 x RER
Very old adult (>11 years) = 1.1-1.6 x RER
Critical care = 1.0 x RER Table 2. Energy available from protein, fat and digestible carbohy-
Weight gain = 1.2-1.8 x RER at ideal weight drate (nitrogen-free extract).
Gestation Metabolizable energy (kcal/g)
Energy requirement increases linearly during gestation in cats. Digestible
Energy intake should be increased to 1.6 x RER at breeding and Species Crude protein Crude fat carbohydrate
gradually increased through gestation to 2 x RER at parturition. All* 4.4 x digest.* 9.4 x digest.* 4.15 x digest.*
Free-choice feeding of pregnant queens is also recommended. Dogs
and cats** 3.5** 8.5** 3.5**
Lactation
Lactation is nutritionally demanding and the physiologic and nutri-
tional equivalent of heavy work. Recommend 2 to 6 x RER Metabolizable energy (kJ/g)
(depending on number of kittens nursing) or free-choice feeding. Digestible
The following table may also be used to estimate the DER of lac- Species Crude protein Crude fat carbohydrate
tating queens: All* 18.41 x digest.* 39.33 x digest.* 17.36 x digest.*
Dogs
and cats** 14.64** 35.56** 14.64**
Weeks of lactation DER
Weeks 1-2 RER + 30% per kitten
Week 3 RER + 45% per kitten Key: digest. = digestibility
Week 4 RER + 55% per kitten *The most accurate value to use when the digestibility of the three
Week 5 RER + 65% per kitten nutrients is known. (Adapted from Lewis et al, 1987)
Week 6 RER + 90% per kitten **“Modified” Atwater values (Dog Food Nutrient Profiles and Cat
Food Nutrient Profiles). Association of American Feed Control
Growth Officials 2007.
Daily energy intake for growing kittens should be about 2.5 x RER.
Free-choice feeding is recommended.