Page 121 - Raw Diet References Book 2019

2.3.4 Breed & type

It has been shown that some breeds such as variation in stature or insulation capacity of skin and
Newfoundland dogs and huskies have relatively lower hair coat, which influences the degree of heat loss.
energy requirements, while Great Danes have a MER However, when data are corrected for age, inter-breed
above the average (Kienzle & Rainbird 1991, Rainbird differences become less important (Finke 1994). Yet
& Kienzle 1989, Zentek & Meyer 1992). Breed-specific NRC 2006 reports Newfoundland dogs, Great Danes
needs probably reflect differences in temperament, and terriers as breeds with energy requirements
resulting in higher or lower activity, as well as outlying the predictive range (NRC 2006a).

2.3.5 Thermoregulation and housing

Cool environment increases animals’ energy During exposure to heat, the basal metabolic rate
expenditure (Blaza 1982, Finke 1991, Meyer & Zentek cannot be lowered (Ruckebusch et al. 1984). If the
2005, NRC 1985, Walters et al. 1993). When kept environmental temperature increases above the
outside in winter, dogs may need 10 to 90 per cent upper critical temperature (UCT), the animal has to
more calories than during summer. get rid of the heat by either increasing blood flow to
the surface (vasodilatation) or enhanced evaporation
Energy needed for maintaining body temperature of water (panting), which also costs energy (Kleiber
is minimal at a temperature called the thermo- 1961b). Vasodilatation becomes ineffective when
neutral zone (TNZ). The TNZ is species and breed the environmental is equal to the rectal temperature
specific and is lower when the thermal insulation is (Kleiber 1961b). The UCT for adult dogs seems to be 30
better. The TNZ has been estimated to be 15-20°C for to 35 °C (NRC 2006b).
long-haired dog breeds and 20-25°C for short haired
dog breeds; it may be as low as 10-15°C for Alaskan Individually housed dogs, with little opportunity
Huskies (Kleiber 1961b, Männer 1991, Meyer & Zentek to move, may have daily energy requirements
2005, Zentek & Meyer 1992). (DER) as low as 70kcal ME/kg0.75. When housed in
kennels together with other dogs and a lot of mutual
Besides insulation capacity, the energy expenditure interaction, which stimulates activity, DER may rise to
also depends on differences in stature, behaviour over 144kcal ME/kg0.75 (602.5kJ/kg0.75) (NRC 2006a).
and activity during cold weather, and degree of
acclimatisation (Finke 1991, Meyer & Zentek 2005, Diet-induced thermogenesis plays a small role;
NRC 1985, Zentek & Meyer 1992), as well as on air it represents about 10 per cent of the daily energy
movement and air humidity (McNamara 1989, Meyer expenditure in dogs. It increases with diets rich in
& Zentek 2005). Animals kept together may decrease protein and is greater in dogs fed four meals per day
the rate of heat loss by huddling together; this than in dogs fed once daily (NRC 2006a).
phenomenon is very important for neonates (Kleiber
1961b).

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