ture, Antibiotics in Agriculture, 1. NAS-NRC

AFRESHLY laid egg has a white which is firm and stands up well. After the shell egg has been kept for a few days at room temperature or for a longer period in cold storage, the broken out egg white contains less firm white (Almquist and Lorenz, 1932; Lorenz and Almquist, 1936) and becomes less viscous and spreads out much more (Evans and Car-ver, 1942b; Evans, 1943). The whites of these older eggs do not stand up well and are considered to be of poorer quality (Wilhelm and Heiman, 1938; Evans and Carver, 1942a). Evidently some changes in the protein structure of the white must occur during storage of shell eggs, because egg white is composed primarily of water and protein. Evans and Bandemer (1956) developed a method for the separation of egg white proteins and their quantitative estimation by filter paper electrophoresis in order to make possible a study of changes in the