BIRCHARD, G.F.*; George Mason Univ.: Effects of Incubation Temperature on Growth and Oxygen Consumption Rate in Bobwhite Quail Eggs
Incubation temperature has been shown to have significant effects on embryonic and postnatal growth and energetics in birds. Bobwhite (Colinus virginanus) eggs were incubated at a constant 37.5 C (control) or at 35.5 C for the first 14 days of incubation and then 37.5 C until hatching (LowT). Over the last 64-70% of incubation embryonic mass and oxygen consumption rate (VO2)were determined regularly. The incubation period for control eggs was significantly less than for LowT eggs (23.2 vs 24.8 d). The period of maximum growth during development was delayed in the LowT group and did not appear to plateau late in incubation. Hatchling wet mass was not significantly different, however, hatchling dry mass was less in the LowT group (1.797 s 1.648 g). Fractional H2O was greater in the LowT group over the entire measurement period. Peak pre-external pipping VO2 (4.9 vs 4.7 ml/h), total oxygen consumed up until pipping, and total oxygen consummed per gram of dry hatchling mass were similar in the two groups. It appears that growth was significantly altered by the varied temperature regime but that the energetics of development remain relatively similar despite the increased incubation time.
