Glucose Tolerance and Lipid Absorption in Guinea Fowl (Numida meleagris) and Domestic Fowl (Gallus gallus var. domesticus)

Research on metabolism in poultry is mainly conducted on domestic fowl and the same physiological response is assumed in Guinea fowl (Numida meleagris). Glucose tolerance and lipid absorption were compared between chickens (Gallus gallus var. domesticus) and Guinea fowl. Twelve Guinea fowl and Chickens were randomly divided into subgroups of 6 each and subjected to an intravenous and oral glucose tolerance test or fat loading tests with medium and long chain fatty acids triglycerides (coconut oil and olive oil, respectively). The mass, glycogen content and lipid content of the livers was also determined. The Guinea fowl had higher (p<0.001) basal glucose levels than chickens. In the Guinea fowl, plasma glucose levels peaked 15 min after the oral glucose load and returned to basal levels (13.9 +/- 1.2 mmol L-1) by 30 min whereas in the chicken plasma glucose levels remained elevated and returned to basal levels (11.2 +/- 0.8 mmol L-1) after 90 min. Plasma glucose levels peaked 10 min after the intravenous administration of glucose in both species and returned to basal levels at 30 min in the chickens and 60 min in the Guinea fowl. Triglyceride levels in the chicken remained below 0.8 mmol L-1 even after the oral fat loading. In the Guinea fowl, plasma triglyceride levels increased after 30 min, peaking at 1.7 +/- 0.4 mmol L-1 (basal level 0.9 +/- 0.1 mmol L-1) at 300 min and although it dropped it did not return to basal levels by 420 min after the administration of the coconut oil. Administration of the olive oil caused non-significant increases (p>0.05) in the triglyceride levels of the Guinea fowl. Chicken livers had a greater mass (p = 0.0002, t-test) and glycogen content (p = 0.0003, t-test) than Guinea fowl livers. The differences in glucose tolerance and lipid absorption indicate that data from chicken cannot be directly extrapolated to Guinea fowl.