Factors Relating to Genetic Differences in the Amount of Chick Allantoic Fluid

THE report of genetic differences in the vaccine yielding capabilities of embryonating eggs (Bell et al., 1964) indicates the need for (1) the identification of the physiological basis of such differences and (2) the detection of genetic variation in normal embryonating eggs which might reflect differences in vaccine yielding potential. Since the vaccine was harvested as allantoic fluid, information on factors influencing the amount of allantoic fluid is of primary concern. Although many genetic studies on traits of the domestic fowl are found in the literature, none refer directly to allantoic fluid. However, factors related to the volume of allantoic fluid have been identified. As water is a major component of allantoic fluid (Romanoff, 1967), and loss of moisture is characteristic of incubated eggs (Quinn et al., 1945), genetic differences in the amount of allantoic fluid could depend inversely on differential moisture losses during incubation. Other factors such as egg…