750 Diseases of the (ienital Organs 



eluded all females which had been fed raw milk and which. 

 under the new plan, received boiled milk. The third group 

 consisted of females born after the recommendation had 

 gone into force, which had received throughout their lives 

 only cooked milk. 



In the first group there were 11 females which were kept 

 in the herd a total of 131 months after they had reached 

 breeding age. They produced 100 healthy pigs — one healthy 

 pig for each 1.28 months, or 9 1/3 pigs a year. The second 

 group comprised 25 sows with a total of 438 breeding 

 months, which had produced 207 healthy pigs, or one for 

 each 2.11 months, equivalent to 5.68 pigs per year. The 

 third group comprised 8 sows (at date of making up statis- 

 tics) which had been kept a total of 92 breeding months and 

 which had produced 107 healthy pigs, or one pig for each 

 0.85 months, equivalent to 14.1 pigs per annum. Accord- 

 ingly the combined efficiency of the two first groups was an 

 average of 6.48 pigs per sow per year as opposed to 14.1 

 pigs per annum in the final group. I have been unable to 

 account for the doubling of the reproductive efficiency ex- 

 cept by the change in the plan of feeding dairy milk. It ap- 

 pears, too, that it was not the feeding of the adult sows 

 which affected the breeding efficiency, but the more hygienic- 

 feeding of the young pigs. This is parallel to my observa- 

 tions upon the health of nursing calves. If the calf is 

 healthy, whether male or female, it will be fertile when it 

 reaches breeding age, but if it has diarrhea or pneumonia 

 as a young calf its fertility as an adult will be low. I do not 

 attribute the higher fertility in the third group to the killing 

 of the Bang organism in the milk fed, nor is there any as- 

 surance that the bacterial content in the milk was directly 

 responsible. It may well have been that the living bacteria 

 in the milk established lesions in the digestive mucosa (nm- 

 co-enteritis, dysentery) which prepared an open portal of 

 entry for bacteria already present in the intestines of the 

 pig, and that these, passing to the genital trait, persisted to 

 sex maturity and impaired reproduction. 



