
What do dogs choose to eat, if they have a choice??
STUDY: Roberts MT, Bermingham EN, Cave NJ, Young W, McKenzie CM & Thomas DG 2018, ‘Macronutrient intake of dogs, self-selecting diets varying in composition offered ad libitum’, Journal of Animal Physiology & Animal Nutrition (Berlin), vol. 102, no. 2, pp. 568-575. doi: 10.1111/jpn.12794.
Aim: determine the macronutrient self-selection in dogs fed over 10 days.
Method:
15 adult dogs were given access to three wet diets providing 500% of daily ME, twice daily over 10 days.
The diets were nutritionally complete and formulated using the same four ingredients in different proportions to supply high levels of protein (58% ME), fat (86% ME) or carbohydrate (54% ME).
Findings:
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when dogs are allowed to self-select from diets varying in macronutrient composition, they will consume at least 30% of their energy from protein.
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Protein intake increased from 29% total energy on day 1 to 44% by day 10.
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This increase in protein intake was associated with a decrease in fat consumption over the experiment, with the dogs consuming 68% on day 1 and 52% by day 10. Thus, the protein:fat ratio increased from 0.45 on day 1 to 0.90 by day 10.
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Carbohydrate consumption remained steady at 3% throughout the study.
Relevance: dogs still possess a "feast or famine" mentality, wherein energy dense fat is prioritised over protein initially. With continued feeding over 10 days, a transition to a more balanced energy contribution from both macronutrients is evident. The study also shows that given the option, dogs do not select carbohydrate to be a significant portion of the diet. The health implications of such dietary selection are of interest.