Edwin C. Voorhies was Associate Professor of Agricultural Economics, Associate Agricultural Economist in the Experiment Station, and Associate Economist on the Giannini Foundation; Gladwin A. Read was Research Assistant in Agricultural Economics, University of California. Resigned December 31, 1925.
Hilgardia 5(17):531-590. DOI:10.3733/hilg.v05n17p531. April 1931.
Constitutional fitness in chickens is gauged primarily by four main criteria: hatchability, livability, rate of growth, and egg production (Warren(18)). The desirability of reliable standards for each criterion for breeds of economic importance. is apparent. This investigation deals with the livability of Single Comb White Leghorns, a race of fowls which from the standpoint of numbers equals and perhaps exceeds the numbers of all other breeds combined (Brown(2)).
It has been held that the most reliable measure of relative livability is given by the percentage of chicks alive three weeks after hatching (Dunn(7)). This study involves the first two weeks of life during the brooding period. However, two weeks seem to provide sufficient time for chicks to demonstrate the vitality of their particular strain. In the western section of the country most chicks go out into the open air when they are approximately 10 days old.
 Brown Edward. Races and breeding of domestic poultry. 1929. 1:1st ed. New York: John Wiley and Sons. 1-408. 68 plates.
 Card Leslie E., Kirkpatrick William F. Rearing chickens. Connecticut (Storrs) Agr. Exp. Sta. Bul. 1918. 96:355-393.
 Charles T. B., Knandel H. C. Rearing chicks in confinement. Pennsylvania Agr. Exp. Sta. Bul. 1928. 218:3-12.
 Dunn L. C. Experiments on close inbreeding in fowls. Connecticut (Storrs) Agr. Exp. Sta. Bul. 1923. 111:139-172.
 Hays F. A., Sanborn Ruby. Vigor in production-bred flocks. Massachusetts Agr. Exp. Sta. Bul. 1928. 242:151-175.
 Pearl Raymond. Introduction to medical biometry and statistics. 1923. 1st ed. Philadelphia and London: W. B. Saunders Company. 379p. 71 figs.