Glucose-insulin relationships and thyroid status of cockerels selected for high or low residual food consumption.
The plasma glucose-insulin relationships and thyroid status were investigated in two lines of adult cockerels divergently selected for high (R+) or low (R-) residual food consumption (RFC). For a given body weight, R+ birds had a 74% higher food intake than R- birds. Plasma glucose concentrations were significantly lower in the R+ line compared with the R- when fasted, whereas R+ birds exhibited a significantly lower plasma insulin concentration than R- birds either in fed or fasted state. After an overnight fast, R+ birds also exhibited a higher sensitivity to exogenous insulin in view of its more pronounced hypoglycaemic effect. After an oral glucose load, the glucose disposal of R+ cockerels was faster despite lower glucose-induced plasma insulin concentration. Whilst plasma triacylglycerol concentrations were lower in the R+ line when fed, plasma non-esterified fatty acid concentrations were higher in fasted R+ than R- cockerels (684 v. 522 mumol/l). Higher plasma triiodothyronine concentrations were observed in fed R+ compared with R- birds (3.0 v. 2.1 nmol/l respectively). The higher plasma concentrations of triiodothyronine associated with lower concentrations of insulin could account for the leanness and the elevated diet-induced thermogenesis previously observed in the R+ line.
Station de Recherches Avicoles, Institut National de la Recherche Agronomique, Nouzilly, France. gabarrou@esa-purpan.fr
J F
JF
Gabarrou
P A
PA
Geraert
J
J
Williams
L
L
Ruffier
N
N
Rideau
D000821:Animal Feed; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D001835:Body Weight / Q000502:physiology; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D007328:Insulin / Q000097:blood*; D008297:Male; D011200:Poultry; D013961:Thyroid Gland / Q000502:physiology*; D014280:Triglycerides / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014527:Uric Acid / Q000097:blood
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D014280:Triglycerides; D014284:Triiodothyronine; D014527:Uric Acid