Changes in Plasma Constituents of Crossbred (Aigamo) Ducks During the Winter Season

Changes in plasma constituents in the crossbred (aigamo) duck (♀ Japanese mallard duck $ ♂ mallard) were successively investigated at two-week intervals during winter from December to March. The pattern of changes in plasma triacylglycerol and glucose were similar over this period. A good correlation between plasma total protein and albumin was detected, but the trend in plasma uric acid correlated better with triacylglycerol and glucose than with total protein and albumin. These five plasma constituents were more closely correlated with the average ambient temperature at 2–4 days before blood sampling than on the day of sampling itself, implying that the metabolic response of aigamo ducks to a change in temperature occurs slowly. The concentrations of plasma constituents recorded in aigamo ducks were similar to the mean values for wild and domestic ducks reported in previous studies.