journal of rnmm research 
Vol. XXIX Washington, D. C., October 15, 1924 No. 8 
POSTNATAL GROWTH OF THE BODY, SYSTEMS, AND 
ORGANS OF THE SINGLE-COMB WHITE LEGHORN 
CHICKEN 1 
By Homer B. Latimer 
Department of Zoology and Anatomy, University of Nebraska 
INTRODUCTION 
The problem of growth has been 
studied in many forms of life and from 
various points of view, and yet many 
of its fundamental aspects are still un¬ 
known or imperfectly understood. A 
great amount of data has been accu¬ 
mulated concerning the growth of 
mammals, but comparatively little 
concerning the lower forms of life. In 
regard to birds, there have been a few 
studies of the growth in body weight 
of the domestic fowl, but little atten¬ 
tion has been given to the growth of 
the individual organs and systems. A 
systematic study of growth has there¬ 
fore seemedd esirable, for various rea¬ 
sons. The domestic fowl (Gallus 
<domesticus) is easily obtained, is omni- 
' vorous, and has a relative^ short 
period of growth. Its economic value 
adds to the importance of a better 
knowledge of its anatomy and of the 
growth changes occurring in its various 
organs and systems during its devel¬ 
opment. 2 
REVIEW OF LITERATURE 
The literature upon the growth of the 
domestic fowl consists chiefly of a 
few reports, giving the average weight 
of a number of birds at certain stages 
of their growth, and usually covering 
only brief periods. 
Petrov (19) z studied the effects of 
hunger on the body weight in fowls, 
including a few observations upon a 
group of normal controls at various 
ages. He does not state the breed 
used and his data are, therefore, of 
little value for comparison. Weiske 
(SO) studied the growth of 11 chick¬ 
ens from 6 days of age to 1 year. 
He later autopsied a newly hatched 
chicken of the same breed. He killed 
and autopsied individual specimens 
at intervals throughout the year and 
recorded the weights of the fresh and 
oven-dried skeletons and the feathers, 
immediately after removal from the 
chicken and again after oven-drying. 
He further studied the chemical com¬ 
position of the feathers and skeletons. 
Houssay (7) studied the growth of a 
number of chickens and plotted 
the growth curves. Stefanowska (23) 
plotted separate growth curves of 
growth in body weight for the males 
and females of a group of chickens. 
Minot (15, 16) followed the growth 
of two male and eight female chickens, 
making weighings daily at first and 
later less frequently up to 190 days; 
then three weighings between * 335 
and 350 days of age. He found an 
initial decrease in weight after hatch¬ 
ing, similar to the postnatal decrease 
in mammals. Lee (IS) made a very 
careful study of the fattening of poul¬ 
try. The time during which the 
maximum gain occurs, the amount of 
feed required, and the average gain for 
several different breeds were deter¬ 
mined. Mitchell and Grindley (17) 
made a study of the same problem for 
poultry as well as for some of the 
larger farm animals. Philips (20) 
published the results of growth ex¬ 
periments during four years upop 
1 Received for publication Mar. 11, 1924—issued January, 1925. This work was done cooperatively by 
the Department of Anatomy of the University of Minnesota and the Divisions of Poultry Husbandry and 
Veterinary Medicine of the Minnesota Agricultural Experiment Station. 
2 This study was undertaken upon the suggestion of Prof. C. M. Jackson and Prof. R. E. Scammon, of 
the University of Minnesota, to whom the writer wishes to express the deepest gratitude for counsel and 
advice during the course of the investigations. The writer is also greatly indebted to Prof. A. C. Smith 
and Prof. C. P. Fitch, of the University of Minnesota, for the generous provision of material and facilities 
for study. 
3 Reference is made by number (italic) to “Literature cited,” p. 396-397. 
Journal of Agricultural Research, Vol. XXIX, No. 9 
Washington, D. C. Oct. 15, 1924 
Key No. Minn.—52 
99185—25f-1 
(363) 
