SCIENCE BULLETIN, No. 12. 



bear out this contention. At the same time, several contributing causes must 

 be considered in connection with osteo-malacia as found in these areas. 

 Foremost amongst these must be placed the method of dairy-farming adopted. 

 The country, never at any time very rich, has been grazed continuously for 

 generations, and during the greater part of this time by the milk-producing 

 breeds of cattle. Very little feed in the way of crops has been grown on the 

 majority of farms, and even when such crops have been grown no artificial 

 manuring has been, as a rule, resorted to. In short, nothing has been done 

 to replace the food material removed by the cattle. 



Again, there is a continued tendency, at all events in the Bega district, to 

 breed with a view to increased milk 'production only, and since in all cases 

 pregnancy and lactation are recognised as increasing the severity of the 

 complaint, it is likely to be still more noticeable amongst cattle which are 

 simply milk-producing machines. 



The investigations so far carried out provide results which are entirely 

 -opposed to the theory of the infectious origin of the complaint. Throughout 

 the whole coast of New South Wales, and especially in the areas now being 

 dealt with, the disease is strictly localised, and in between the affected areas 

 are stretches of better country, in which the cattle are never affected, 

 although there is a continuous interchange of cattle between all parts of the 

 district. Very many instances were noted in which cattle from affected 

 herds and affected cattle themselves were removed from affected to non- 

 affected areas without spreading the disease, and, on such removal, those that 

 were affected rapidly recovered. 



Symptoms. 



As observed in cattle in New South Wales the symptoms follow the 

 classical description very closely. The most marked, and generally the first, 

 sign is a perverted appetite, the cattle seeking out and chewing bones, sticks, 

 shells and other objects, but preferably bones, for which they exhibit an 

 extraordinary craving. The affected animals move stiffly, this stiffness being 

 most noticeable in the hindquarters, and they are often lame. In some 

 instances swellings are noticed at the fetlocks and lower joints of the feet. 

 The back is often arched and the loins sunken. The animal has a general 

 unthrifty appearance, the coat is harsh and dry, and a progressive emaciation 

 is observed. The secretion of milk decreases and finally stops. 



Fractures occur readily, especially of the ribs and bones of the limbs, and 

 such fractures heal very imperfectly. The animals finally die from 

 exhaustion. 



Course. 



The course of the disease is usually chronic, but it is subject to compara- 

 tively sudden aggravations during pregnancy and lactation. 



