INHERITANCE in SWINE 1 
By Edward N. Wentworth, 2 formerly Professor of Animal Breeding , and Jay L. 
Lush,* formerly Fellow in Animal Breeding , Kansas State Agricultural College 
The genetic studies on swine described herein were begun on a rather 
extensive scale at the Kansas Agricultural Experiment Station in 1914, 
reached their maximum in the spring of 1917, at which time the senior 
author entered military service, and came to an end in the spring of 
1918, when the junior author also assumed military duties. 
With the exception of the second wild boar (PI. 1, A), which is now 
the property of the Iowa State College, none of the swine used in this 
investigation are still living, and hence no further work can be done 
toward solving the unfinished problems, except by beginning once again 
with a new group of individuals. Since there is no immediate prospect 
of this being done, it is thought best to publish the results secured, 
together with the most probable interpretation of them, although it is 
frankly admitted that the data do not furnish a definite solution of the 
problems attacked and that in some cases they do little more than 
indicate the general direction for future work. 
Because there have been so few carefully controlled genetic experiments 
on swine it is felt that there is need to make this material available for 
further study, even though many of the problems touched upon have 
not been settled. This paper, therefore, is presented as a report of 
progress. 
PURPOSE AND PLAN OF THE EXPERIMENTS 
The purpose of the experiments was to investigate the mode of inheri¬ 
tance of certain well-defined characters in swine, such as the shape of 
face, set of ears, color, mammary pattern, growth factors, and the size 
of litter. On all these points, except size of litter, the principal work 
was done on the descendent generations from crosses of a registered 
Berkshire boar by Tamworth and Duroc-Jersey sows. The problem of 
litter size was separately attacked through mating European wild boars 
of the Schwarzwald type to registered Tamworth and Berkshire sows. 
The production of a large F 2 generation and the making of suitable 
back crosses were planned, but only a single F 2 litter from the wildX 
Tamworth cross and none from the Wild X Berkshire or Berkshire X 
Tamworth cross had been secured when the work was discontinued. 
Hence the majority of the data will concern the Berkshire X Duroc- 
Jersey cross, from which a large F 2 generation and a considerable number 
of back cross individuals were obtained. 
1 Accepted for publication Jan. 16, 192a. Paper No. 31 from the Department of Animal Husbandly, 
Kansas Agricultural Experiment Station. Acknowledgment is hereby made of the invaluable assistance 
of C. E. Aubtrl, who for a period of two years collected much of the data of this investigation. 
* Now in charge of live-stock research and economics for Armour and Company. 
* Now Auimal Husbandman, Texas Agricultural Experiment Station. 
Journal of Agricultural Research. 
Washington, D. C. 
ad 
Vol. XXIII, No. 7 
Feb. 17, 1923 
Key No. Kans.-a 8 
(557) 
