666 Diseases of the Genital Organs 



purposes, the saving of the life of a calf is an utterly worth- 

 less performance unless there be added the safeguarding of 

 sexual health. Few if any principles regarding the infec- 

 tions of the genital organs of cattle are clearer today than 

 that the fertility of a bull or heifer, when arrived at breed- 

 ing age, has been fixed unalterably during its nursing period. 

 The most important result to be sought in the rearing of 

 calves is not the conservation of their lives, but the control 

 of infection which constantly tends to attain a habitat in the 

 genital system of both sexes, where it persists until breed- 

 ing age, when it may prevent reproduction or, infinitely 

 worse, may prove a serious menace to other animals with 

 which the infected animal comes into sexual relations. This 

 danger is disputed by many and ignored by nearly all breed- 

 ers and veterinarians, but the evidence which has been ac- 

 cumulated is so strong that it is at least time to give to the 

 subject thoughtful attention. It is common knowledge that 

 in large herds where sterility, abortion, metritis, retained 

 fetal membranes, and other phenomena of this group are 

 violent, the calves suffer much from dysentery and pneu- 

 monia. When heifers in these herds reach breeding age, it 

 is notorious that upon the average it requires more than 

 twice the number of copulations to produce pregnancy than 

 is necessary in adult cows. Once pregnant, heifers which 

 have been unhealthy as calves abort in a ratio two to three 

 times as high as observed in cows. On the other hand, in 

 small grade herds where often sterility and abortion are 

 rare and the calves are healthy, the heifers upon reaching 

 breeding age conceive as promptly as cows and carry their 

 calves as safely. There are also reliable statistical data sup- 

 porting this position, an example of which is shown in the 

 chart designated Fig. 207. The herd was a large one. the 

 records are unusually complete and accurate, the duration of 

 time covered by the data is extensive, and the difference in 

 the behavior of the two groups of heifers is distinct and re- 

 markable. They were kept in the same stables and pastures, 

 were bred to essentially the same bulls, were the progeny of 

 the same group of cows as nearly as possible, and were in 



