The purpose of this study was to characterise amino acid requirements and amino acids
bioavailability for dogs with the help of a literature review. Very little information about
amino acid requirements and amino acids bioavailability for dogs could be found.
Various methods have been developed to determine the bioavailability of amino acids in
feedstuffs and no single procedure has emerged as universally applicable. Bioavailability of
D-methionine is usually equal to the L-isomer and D-methionin is well utilized by dogs.
Bioavailability of D-tryptophan is 36 % by dogs. Other amino acids do not undergo inversion
and therefore cannot be utilized.
Ileal digestibilities of amino acids have been shown to vary tremendously. True ileal
digestibilities of arginine varied from 77 % to 87 %, of cystine from 29 % to 69 %, threonine
from 52 % to 78 % and lysine from 62 % to 84 %.
Ileal digestibility by dogs in comparison with prececal digestibility by broilers is higher,
except of the amino acid cystine. Ileal digestibility of arginine, histidine, leucine, phenylalanine,
threonine, and cystine by pigs is higher than by dogs.
The apparent fecal digestibility method is not an accurate method for the measurement of
the absorption of crude protein and certain amino acids from canine diets.
Addition of free available tyrosine to the foods can prevent the Red hair syndrome in dogs
and optimize hair pigmentation. Taurine supplementation may result in prolonged survival
times in dogs with low plasma taurine concentrations. Methionine supplementation
increased plasma concentrations of taurine.
Comparing the results from different studies about bioavailability and requirement of
protein and amino acids with the recommendations of NRC, AAFCO and FEDIAF has shown
that the recommended values are adequate for optimal growth, feed utilization and
Proteins and amino acids requirements for growing puppies and dogs in reproduction are
considerably higher compared to requirements for adult dogs at maintenance.
Comparing the recommendations of NRC, AAFCO and FEDIAF, NRC recommends lower
amounts of proteins and amino acids than AAFCO and FEDIAF, but those amounts are still
within the limits worked out in different studies.
Further studies of the availability of amino acids and amino acids requirements for dogs are
needed to be able to prepare food which meets the requirement as accurate as possible.