TY - JOUR
T1 - The effect of excesses and deficiencies in amino acids on the feeding behaviour of the common brushtail possum (Trichosurus vulpecula)
AU - DeGabriel, J.
AU - Foley, W. J.
AU - Wallis, I. R.
PY - 2002
Y1 - 2002
N2 - In this study of the amino acid nutrition of a marsupial we tested three hypotheses: (a) that brushtail possums eat less when diets contain excesses or deficiencies in essential amino acids, (b) that brushtail possums choose diets that do not contain amino acid excesses, and (c) that amino acid consumption is mediated partly by the 5HT3 receptor. Possums ate less when 0.2–1.0% methionine (wet matter) was added to the diet, but similar concentrations of lysine and threonine had little effect. However, when given a choice, possums always selected the basal ration over one with added lysine, methionine or threonine at concentrations between 0.05% and 0.9%. In contrast to the experiments with excess amino acids, possums did not eat less of a diet almost devoid of an essential amino acid. Instead, the possums ate less when their diets contained synthetic amino acids rather than similar amounts and proportions of amino acids as casein. Contrary to the third hypothesis, the 5HT3 receptor antagonist, ondansetron, did not affect feedingby possums given a diet containing 0.8% methionine, suggesting that post-ingestive feedback, via the 5HT3 receptor, does not regulate amino acid intake when diets contain amino acid excesses.
AB - In this study of the amino acid nutrition of a marsupial we tested three hypotheses: (a) that brushtail possums eat less when diets contain excesses or deficiencies in essential amino acids, (b) that brushtail possums choose diets that do not contain amino acid excesses, and (c) that amino acid consumption is mediated partly by the 5HT3 receptor. Possums ate less when 0.2–1.0% methionine (wet matter) was added to the diet, but similar concentrations of lysine and threonine had little effect. However, when given a choice, possums always selected the basal ration over one with added lysine, methionine or threonine at concentrations between 0.05% and 0.9%. In contrast to the experiments with excess amino acids, possums did not eat less of a diet almost devoid of an essential amino acid. Instead, the possums ate less when their diets contained synthetic amino acids rather than similar amounts and proportions of amino acids as casein. Contrary to the third hypothesis, the 5HT3 receptor antagonist, ondansetron, did not affect feedingby possums given a diet containing 0.8% methionine, suggesting that post-ingestive feedback, via the 5HT3 receptor, does not regulate amino acid intake when diets contain amino acid excesses.
KW - feeding
KW - lysine
KW - marsupial
UR - http://handle.uws.edu.au:8081/1959.7/uws:30652
U2 - 10.1007/s00360-002-0289-5
DO - 10.1007/s00360-002-0289-5
M3 - Article
SN - 0174-1578
VL - 172
SP - 607
EP - 617
JO - Journal of Comparative Physiology B
JF - Journal of Comparative Physiology B
IS - 7
ER -