October 31, 2016

Evaluation of the Energy Requirements of Adult Kennel Dogs

image source: http://www.dogwallpapers.net/siberian-husky/siberian-husky-puppies-photo.html

               This study sought to compare the energy requirements suggested by the National Research Council (NRC) to the actual energy requirements of adult kennel dogs. These researchers wanted to determine the accuracy of the formula used by the NRC to define the suggested energy requirements for different breeds, because it did not consider nutritional factors such as animal age, housing conditions, weight change over time, or the actual metabolizable energy in the dog’s diet. They set up a 54-week experiment using 18 dogs: 6 Beagles, 6 Labrador Retrievers, and 6 Siberian Huskies. These dogs were housed in groups of three in half indoor, half outdoor spaces, were all fed the same diet of commercial dry dog food (ALP Beef Flavored Dinner), and were weighed weekly. Researchers determined the metabolizable energy content of this diet by analyzing the feces of a separate test group also fed the same amounts of the same dry food.

               After the 54-week period, the energy requirements of each respective breed were determined based on the experimental data collected, and was then compared to the energy requirements suggested by the NRC’s formula. All three breeds showed that the formula was inaccurate and that it greatly overestimated the amount of energy required by each breed. Siberian Huskies showed the most variation, probably due to their significantly greater genetic diversity and the range of base body weights and ages included in this experiment.

This study also analyzed differences in energy requirements from month to month, corresponding to changes in outdoor temperature. The researchers found different results for Siberian Huskies than for Labs or Beagles. Huskies had the highest energy intake in September and lowest intake in July, whereas the Labs and Beagles has the highest energy intake in January and lowest intake in June. They attributed this to initial challenges in adjusting food intake to maintain the Huskies’ body weights. However, they did find that energy intake significantly correlated with outdoor temperatures for Beagles and Labs, but not for Huskies. This was somewhat surprising to researchers because all three breeds were housed in the exact same environmental conditions. However, they realized that these environmental differences could be explained by differences in hair length between the breeds, and the ways the breeds were adapted to handle the cold. For example, it was likely that Labs and Beagles spent more time inside during periods of extreme cold, reducing their energy needs. However, these behavioral patterns were not tracked in this experiment. Researchers suggested that this could further be explained by the fact that Huskies can control their body temperature by growing a thicker coat in the winter and shedding the excess hair in longer months in a way that Labs and Beagles cannot. This could be a possible explanation for why Huskies energy intake did not seem to be correlated to changes in outdoor temperature.

Lastly, this same diet was fed to young Labs who were not included in the other data set because they were not housed in this same experimental housing set-up and were used for breeding throughout the 54 week period. However, after analyzing their data, they noticed that the young Labs’ results matched more closely with those of young Huskies than older Labs, suggesting that age may play more of a factor in energy intake than breed.

Overall, the results of this experiment showed that the formulas used by the NRC to estimate energy intake are inaccurate and must consider other external factors such as age and size, that energy requirements for certain breeds may depend on seasonal variation, and that age may play a larger role in energy requirements for dogs of similar size than breed. 

Reviewed by Sarah Slayton 

Full article: http://jn.nutrition.org/content/121/11_Suppl/S22.long

Finke,  Mark D.

J. Nutr.

vol. 121 no. 11 Suppl S22-S28