Interpretive Summary: Minimum dietary methionine requirements in adult dogs
By: Anne Kamiya, MS
Methionine (Met) is an essential amino acid (AA) in dogs, meaning it is required in the diet for good health and proper physiological function. It is also a limiting AA so depending on feed ingredients, Met may be naturally less abundant than other essential AA. The authors of this recent Journal of Animal Science study note that current recommendations by the National Research Council (NRC) are based on studies on the minimum requirements (MR) of Met in immature, growing dogs, which may or may not be broadly applicable to different breeds of adult dogs. The goal of this study was to determine the MR for Met in three different adult dog breeds via the indicator AA oxidation (IAAO) technique. The authors hypothesized that MR of Met would differ based on breed.
Three dog breeds of different sizes (Miniature Dachshund, Beagle and Labrador Retriever) were fed a low protein diet deficient in Met, but with excess of the AA Cysteine. The diets were then supplemented with Met in different concentrations to determine the MR of Met. Miniature Dachshunds had different MR for Met than Beagles and Labrador Retrievers, with the latter two breeds having a higher MR for Met.
Overall, the results of this study suggest that the MR for Met in dogs may vary by maturity and size, supporting the authors’ hypothesis. The authors concluded from these results that the MR for Met in adult Beagles and Labrador Retrievers is higher than current NRC recommendations. Considering the small size of this study (12 dogs total) and the potential significant changes that may result to dietary recommendations for Met in adult dogs, more comprehensive studies reconfirming these results and further evaluating the MR of Met in adult dogs of different sizes and ages is warranted.
The original article, Minimum dietary methionine requirements in Miniature Dachshund, Beagle, and Labrador Retriever adult dogs using the indicator amino acid oxidation technique, is viewable online in the Journal of Animal Science.