A biometrical study of the mortality of Single-Comb White Leghorn chicks
AuthorsEdwin C. Voorhies
Gladwin A. Read
Authors AffiliationsEdwin 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.
PDF of full article, Cite this article
Abstract does not appear. First page follows.
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.
 Beach J. R., Michael S. T. Pullorum disease. California Agr. Exp. Sta. Bul. 1930. 486:1-31. http://archive.org/details/pullorumdiseaseb486beac
 Brown Edward. Races and breeding of domestic poultry. 1929. 1:1st ed. New York: John Wiley and Sons. 1-408. 68 plates.
 Bunyea H., Hall W. J. Some observations on the pathology of bacillary white diarrhea. Jour. Amer. Vet. Med. Assn. 1928. 75 N.S. 28:581-591. 1929
 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.
 Dougherty J. E., Belton H. L. Poultry houses and equipment. California Agr. Exp. Sta. Bul. 1929. 476:1-100. http://archive.org/details/poultryhousesequ47629doug
 Dunn L. C. Hatchability and chick mortality. Poultry Sci. 1921-22. 1:33-38. DOI: 10.3382/ps.0010033 [CrossRef]
 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.
 Jull M. A. Studies in hatchability. Poultry Sci. 1928. 1:196-215. DOI: 10.3382/ps.0100327 [CrossRef]
 Lippincott W. A. Poultry production. 1927. 4th ed. Philadelphia: Lea and Febiger. viii + 602p. 205 figs. 2 plates. DOI: 10.5962/bhl.title.49254 [CrossRef]
 Mills Frederick C. Statistical methods. 1924. 1st ed. New York: Henry Holt and Company. xvi + 604p. 87 figs. DOI: 10.2307/2281354 [CrossRef]
 Parker Sylvia L. Effects of early handicaps on chickens as measured by yolk absorption and body weight to twenty weeks of age. Hilgardia. 1929. 4:1-56. DOI: 10.3733/hilg.v04n01p001 [CrossRef]
 Pearl Raymond. Introduction to medical biometry and statistics. 1923. 1st ed. Philadelphia and London: W. B. Saunders Company. 379p. 71 figs.
 Pearl Raymond. Duration of life as an index of constitutional fitness. Poultry Sci. 1923. 3:1-10. DOI: 10.3382/ps.0030001 [CrossRef]
 Roberts E., Card L. E. The inheritance of resistance to bacillary white diarrhea. Poultry Sci. 1926. 6:18-23. DOI: 10.3382/ps.0060018 [CrossRef]
 Voorhies Edwin C. The California poultry industry: a statistical study. California Agr. Exp. Sta. Bul. 1926. 413:1-172. http://archive.org/details/californiapoultr413voor
 Warren D. C. Hybrid vigor in poultry. Poultry Sci. 1927. 7:1-8. DOI: 10.3382/ps.0070001 [CrossRef]