ECONOMIC IMPORTANCE AND ETIOLOGY 19 



have recorded cases in Jerseys, Welsh, Shorthorn, and 

 Devon cattle. The present writers have investigated 

 cases in Shorthorns, Devons, Jerseys, and Herefords. 



There seems to be but little doubt that in Denmark 

 a greater percentage of Jersey cattle is affected than of 

 the native breeds. This is shown by the Kustos 

 Insurance Company in the figures relating to the 

 compensation for losses due to Johne's disease in 

 Jersey and Danish cattle. In 40 herds of Jersey cattle 

 insured, the compensation paid was 28,000 kroner, and 

 in 20 herds of native cattle, 6,000 kroner ; from which 

 it would appear that the disease is roughly twice as 

 prevalent in Jersey cattle as in the native races. 



Miessner and Trapp have made a very careful study 

 of the condition, and consider it to be a stall disease 

 (Stallseuche), or a disease occurring in animals kept 

 housed for a great part of the year. 



In a herd of Hereford cattle kept specially for beef 

 purposes, the proportion of old cattle is very small 

 when compared with the proportion of aged cows in 

 a herd of Jerseys or milking Shorthorns. Where the 

 sole or chief object is to produce milk, the animal is 

 kept housed for a great part of the year, and especially 

 is this the case in Denmark, where the system of dairy 

 farming is more intensive than in England. It is also 

 well known that farmers prefer to house their cows, 

 with the idea that the greater warmth avoids the loss 

 from the utilization of food for maintaining the animals' 

 temperatures, and that by this means a better yield of 

 milk is obtained. Then again, in a milk breed it is 

 necessary for each cow to calve regularly, and the 

 strain on the animal economy is very great. The 

 well-known tendency of Johne's disease to appear 

 suddenly soon after calving may be ascribed to the 

 drain on the cow (she being already slightly affected 



