Urinary energy losses in dogs fed commercial extruded foods.
Energy and nitrogen losses in the urine were recorded in 134 individual balances with adult (1- to 2-year-old) female Beagles that were fed 23 dry extruded dog foods ranging in crude protein (CP) content from 242 to 360 g/kg dry matter. The energy equivalent of urinary nitrogen was estimated as 33.9 kJ/g N. Both energy losses in the urine corrected for the nitrogen balance, and the metabolizable energy (MEn): digestible energy (DE) ratio were found to be closely related to diet CP content (r : 0.851 and 0.820). The MEn content of extruded dog foods can be accurately calculated from the DE content, either by subtracting 4.59 MJ/kg CP or estimating the MEn/DE ratio from the food CP content by the following equation: MEn/DE=0.98 - 3.44 +/- 0.517 x CP (kg/MJ DE).
[Estimation of nitrogen-corrected metabolizable energy value of laboratory canine diets].
This study evaluates the reliability of the equation, metabolizable energy (ME) = digestible energy (DE) - 1.25 x digestible crude protein (DCP), as a means of estimating the energy value of non-purified diets for laboratory dogs. To do this, five digestion and nitrogen-balance (NB) trials and determination of the energy value of a diet were conducted using five diets and four mature, male Beagles for each experiment. The resulting digestibility of crude protein, acid ether extract, and nitrogen-free extract of these diets were 79.5%, 91.6%, and 84.8%, respectively. The NB in every diet was positive: 1.4-8.6 mg/g dry matter of ingested diet. Of the nitrogen (N) ingested, 21% was excreted into feces, 66% was excreted into urine, and 13% was retained. In terms of dietary gross energy (GE), 18% was lost in feces and 5% was excreted into urine leaving 77% as ME. Retained energy in the body was only 1%, and N-corrected metabolizable energy (MEn) was 76% of GE. The average urinary energy (UE) loss per gram of urinary N was 7.84kcal. The correlation between UE/DCP and NB values is statistically significant: UE/DCP = 1.24-0.03NB, r = 0.798, P < 0.001. Therefore, UE/DCP is 1.24kcal/g at N-equilibrium, almost the same as the factor in the above equation. The ME value calculated by the equation is identical to the MEn value and both are significantly lower (P < 0.05) than the empirically determined ME value.(ABSTRACT TRUNCATED AT 250 WORDS)
Evaluation of the energy requirements of adult kennel dogs.
The objective of this experiment was to compare the energy requirements of healthy adult kennel dogs to those recommended by the National Research Council (NRC). The energy requirements of six beagles, six Siberian huskies and six Labrador retrievers were determined over a 54-wk period. Dogs were housed in groups of three in heated indoor-outdoor runs and fed a complete and balanced commercial dry dog food. Beagles had an average daily energy intake of 3414 kJ/dog with monthly averages ranging from 3146 to 3740 kJ/dog. Siberian huskies had an average daily energy intake of 5021 kJ/dog. Average monthly energy intakes ranged from 4715 to 5238 kJ/dog. Labrador retrievers had an average daily intake of 5611 kJ/dog with monthly averages ranging from 5063 to 6623 kJ/dog. Seasonal variation appeared to affect the breeds differently, with long-haired Siberian huskies showing less seasonal variation than the shorter-haired breeds. For all dogs energy intake (kJ/kg body weight 0.75) declined with age. The energy intake of each group of dogs was considerably below that recommended by the NRC. The reason for this discrepancy is unknown, although these data suggest that environmental conditions, breed and/or age play an important role.