832 CYCLOPEDIA OF LIVE STOCK AND COMPLETE STOCK DOCTOR. 



It appears to be more or less prevalent throughout the country. Dr. 

 Leonard Pearson, state veterinarian of Pennsylvania, in his report for 

 1908 states that abortion was never so prevalent as it is to-day. Doctor 

 Barnes, of the Kansas Station, reported the disease to be quite common 

 in Kansas in 1906, and Professor Wilson, of the Arizona Station, reports 

 it to be present in a number of herds in that State. 



The disease occurs more frequently in dairy herds than in any others, 

 although beef cattle, sheep, horses, and goats may become infected. The 

 prevalence of this disease in dairy herds is probably due to the weakened 

 condition of dairy cows caused by the continuous drain of giving milk. 

 Recent reports from the Storrs and New Mexico stations discuss its occur- 

 rence and eradication from the station herds. 



At the Storrs Station the disease was introduced into the herd through 

 the purchase of six pure-bred pregnant animals, two of which aborted 

 shortly afterward. During the next three years 24 of the 79 calvings 

 were premature births. This indicates that the contagion was not ex- 

 tremely virulent or that the treatment delayed to some extent the progress 

 of the disease. 



The premature births occurred at from 145 days to 262 days from time 

 of conception, and the average of the 24 cases was 211 days. The bull 

 was not the sole means of spreading the disease in this instance. The 24 

 conceptions that terminated in premature births were the result of the 

 matings of 15 different sires, eight of which were owned by parties remote 

 from the affected herd. 



At the Arizona Station the disease appears to have been originally 

 communicated by the herd bull. Five cows aborted in the farm herd, 

 of which four were sold for beef and one retained for experimental pur- 

 poses. Under strict sanitary conditions this cow was served by the herd 

 bull and in due time dropped a living calf. A number of cows have 

 since been served by this bull without signs of abortion. 



At the Storrs Station, in order to determine the value of aborting cows 

 as milk producers, the milk and fat yields of ten cows following a normal 

 calving are compared with the milk and fat yields during the period of 

 abortion. 



These cows, following a normal calving, averaged 5,892 pounds of milk 

 and 282.8 pounds of fat in one year. During the next 2.1 years, or from 

 one normal calving to the next normal calving, which included the abort- 

 ing period, these cows averaged 5,196 pounds of milk and 268.4 pounds 

 of fat per year. The milk was 696 pounds, or 12 per cent less per year 

 during the aborting period. These ten cows aborted seven months 

 (averaged 211 days) after conception. The satisfactory yields are at- 

 tributed in part to the complete removal of the afterbirth and the 

 thorough disinfection of the animals after abortion. 



