Page 63 - Small Animal Clinical Nutrition 5th Edition

Macronutrients 63

during growth. The time taken to reach maturity in dogs Table 5-3. Influence of low environmental temperatures on daily
VetBooks.ir increases with increasing mature body weight. The highest Increase Environmental
energy requirement (DER).
energy requirement for puppies occurs at weaning. Growing
puppies require 3 x RER from weaning until four months of
temperature
(%)
age and 2 x RER from four months of age until the puppy Breed in DER Low Normal
Labrador retrievers
reaches adult size.
and beagles 25 (12-43)* 8.5°C (47.3°F) 15°C (59°F)
Much research has been done in mammals to evaluate how Great Danes 22** Winter Summer
food energy intake affects the composition of growth (i.e., body Shorthaired dogs 95*** 7.6°C (46°F) 25°C (77°F)
Longhaired dogs 59.5*** 7.6°C (46°F) 25°C (77°F)
composition, fat vs. lean). Energy consumed during growth †
Beagles 70.5 -17°C (1.4°F) 17°C (62.6°F)
influences the proportion of lean and fat gain during growth. Alaskan sled dogs 61.5 † -17°C (1.4°F) 17°C (62.6°F)
The metabolic efficiency of converting dietary fat to body fat for *Blaza SE. Energy requirements of dogs in cool conditions.
Canine Practice 1982; 9: 10-15.
storage is higher than the efficiency of converting dietary carbo-
**Zentek J, Meyer H. Energieaufnahme adulter Deutscher Doggen.
hydrate or protein to body fat.This finding has been reported to Berliner und Münchner Tierärztliche Wochenschrift 1992; 105:
occur in puppies when comparing the effects of high-fat and 325-327.
***Meyer H. Energie und Nährstoffe–Stoffwechsel und Bedarf. In:
low-fat foods (Romsos et al, 1976). Puppies consuming a high-
Ernährung des Hundes. Stuttgart, Germany: Eugen Ulmer,
fat food had similar growth in lean body mass compared with 1990; 99.
that of puppies fed foods lower in fat, but deposited more body † Durrer JL, Hannon JP. Seasonal variations in caloric intake of
dogs living in an arctic environment. American Journal of
fat (Romsos et al, 1976). The prioritization of growth results in
Physiology 1962; 202: 375-378.
energy being preferentially used for protein growth and second-
arily for fat gain. Excess energy with resulting obesity has been
incriminated as a factor contributing to degenerative joint dis-
ease (Chapters 27 and 34).Developmental orthopedic disease in 1990; Finke, 1991). This effect may also be due to increased
growing large- and giant-breed puppies is a frequently encoun- body fat and less lean body mass resulting in reduced RER. In
tered problem (Chapter 33). studies, dogs over seven years of age required 10 to 20% less
The energy requirements of growing kittens follow a similar energy than those three to seven years of age (Kienzle and
pattern as that for puppies.The highest energy requirement per Rainbird, 1991; Finke, 1994; Harper, 1998). It is important to
unit of body weight occurs at about five weeks of age (Miller note that senior dogs derive energy from their diets just as
and Allison, 1958). Energy recommendations for growing kit- efficiently as young adult dogs. Because MER declines by
tens approximate 2.5 x RER. approximately 15 to 20% and energy digestibility remains
constant, senior dogs should be offered foods providing a 15
Reproduction (Gestation and Lactation) to 20% caloric reduction (Kienzle and Rainbird, 1991; Finke,
In dogs, most of the fetal weight gain occurs in the last third 1994; Harper, 1998). However, it is important to realize that
of pregnancy; therefore, the energy requirement of the bitch there are exceptions to this rule. For example, physical activi-
does not increase markedly until then. DER during gestation ty in a senior dog may offset the age-associated reduction in
approximates 3 x RER for most breeds, although larger breeds MER (Harper, 1998a).
may require more energy than this to maintain normal body Generally, people assume that senior cats are more likely to
condition. In cats, energy intake increases incrementally from be obese because their physical activity decreases with age. As a
the start of gestation and continues up to parturition result, it is often suggested that senior cats be fed energy-
(Loveridge, 1986). restricted foods. One study in cats ranging from one to nine
Lactation is one of the most energy-demanding lifestages for years showed no apparent correlation between increasing age
animals. Depending on the size and age of the litter, DER can and changes in body composition (Munday et al, 1994).
increase as much as 6 x RER for cats and 8 x RER for dogs. Another investigator found no significant effect of age on ener-
Lactation lasts approximately six weeks in dogs and cats. The gy requirements of cats (Burger, 1994). Although these data
energy intakes for dogs and cats during reproduction are sum- indicate that energy requirements of cats do not decline with
marized in Chapters 15 and 22. age as with dogs, the greatest proportion of overweight cats are
older than four and less than 11 years (Armstrong and Lund,
Age 1996; Kronfeld et al, 1994; Scarlett et al, 1994). There appears
Apart from lactation and imposed activity during work or to be a reduction in the percentage of obese cats after age 11
sport, age may be the single most important factor influenc- and a shift towards cats being underweight. The increase in
ing DER of adult pet dogs (Finke, 1994). Three groups of numbers of old thin cats could be the result of the early death
adult dogs can be distinguished: 1) young (one to two years of middle-aged obese cats (Harper, 1998a).
old), 2) middle aged (three to seven years old) and 3) older Dogs and cats over 11 years of age tend to be thinner and
(more than seven years of age) (Kienzle and Rainbird, 1991; have less body fat than those between seven and 11 years old.
Finke, 1994; Rainbird and Kienzle, 1990). Older animals typ- Similar to that found in people, the lean body mass of dogs and
ically need fewer calories to maintain body weight and condi- cats declines with age (Armstrong and Lund, 1996; Harper,
tion, primarily because of decreased activity (Meyer, 1983, 1998a; Jewell et al, 1996). A study investigating the effects of