M.— AGRICULTURE. 241 



deficient in any mineral, that deficiency will be reflected in the diet of the 

 animal. 



In recent years it has been found that large portions of the earth's 

 surface are deficient in some mineral or other which is essential for the 

 normal health and growth of animals. This subject was discussed by 

 Dr. J. B. Orr, himself a pioneer in this field of work, in his presidential 

 address to this Section five years ago. 



In South Africa as well as in other African territories and in Australia 

 the most serious deficiency is that of Phosphorus. Theiler and his co- 

 workers have investigated the ill effects of this deficiency on cattle very 

 fully. They have shown that cattle grazing on phosphorus-deficient 

 pastures develops a depraved appetite for bones and other carcase debris, 

 and this may lead to the ingestion of toxic material with fatal results 

 (' lamsiekte ' in South Africa) ; further, that such cattle remain stunted 

 in growth, are late in maturing, are frequently unfertile, produce very 

 little milk, and are very susceptible to various diseases. By the addition 

 of a small daily ration of phosphorus to the diet, they were able to bring 

 about an almost miraculous improvement in the condition of the animals. 



As a result of the general feeding of phosphorus compounds in the 

 deficient areas of South Africa, the disease ' lamsiekte,' which a dozen 

 years ago caused enormous losses, has practically disappeared and cattle 

 farming in those areas has again become profitable. The significant fact 

 may be recorded here that the village of Vryburg in Bechuanaland, where 

 ten years ago milk was very scarce, to-day owns a creamery which 

 handles a larger volume of cream than any other creamery in South 

 Africa. 



In other countries, where other deficiencies occur, equally striking 

 results have been obtained. Attention need only be directed to the work 

 of Aston in New Zealand on iron deficiency, and the recent brilliant 

 researches of Orr and his co-workers at the Rowett Research Institute on 

 the whole problem of mineral deficiencies. 



B. Other Veterinary Problems. 



At the beginning of this paper mention was made of Dr. Gordon's 

 presidential address in which the need for further research into problems 

 of animal diseases, animal nutrition and animal breeding was emphasized. 



In regard to animal diseases the examples quoted in the preceding 

 section show that considerable advance has been made during the years 

 that lie immediately behind us. Many diseases have been conquered, but 

 many others still await solution. Meanwhile these diseases cause enormous 

 losses and even threaten the adequate supply of the world's markets with 

 meat and other animal products. 



Problems in connection with the niitrition of animals are now receiving 

 attention in many countries. The vast importance of correct feeding can 

 be illustrated best by referring again to the phosphorus deficiency which 

 exists in the pastures of South Africa and other countries. The astounding 

 results which have been achieved with the addition of a small quantity 

 of phosphorus compounds to the ration of the animals promise to 

 revolutionize the beef and dairy industries in those countries. 



Animal breeding also presents problems of great importance and these 

 1930 



