XIIl] FEMALE GENERATIVE ORGANS 199 



during which it exercises a stimulating influence over the mam- 

 mary tissue. 



Ovariotonn' or spajang is practised on the sow in order to 

 promote growth or fattening but this is only done in some parts 

 of the country and by no means ha})itually. It has been fairly 

 estabUshed however that when the operation is done properly 

 the results are commerciallj' profitable. Faulty spaying in 

 which ovarian tissue is left behind has helped to discredit the 

 practice, and this result has been unfortunate. The sows should 

 be operated on at about seven weeks old or the same age 

 as that at which the males are castrated. Hobday recommends 

 ovariotomy for troublesome mares to render them easy to work 

 during oestrus and has obtained some useful results. Ovariotopay 

 is only very rarely performed on the cow but when done during 

 lactation leads to long-continued milk secretion as just mentioned. 



