162 VETEEINAKY HYGIENE 



due to feeding on large quantities of bran, which is produc- 

 tive of calculi from the amount of insoluble salts it contains. 



To all these causes of dirty feeding may be added the 

 presence of nails, wire, needles, and other metallic sub- 

 stances mixed with the corn by accident. To such an 

 extent may these be found, that some large employers of 

 horse labour pass the whole of their corn over an electric 

 plate in order to get rid of them. 



There can be no doubt of the great saving effected in 

 large establishments by thoroughly cleansing grain before 

 giving it as food. The small purchaser is not so liable to 

 obtain foreign bodies and dirt, as the larger consumer who 

 buys by the ton at a special contract rate. 



PAEASITES AFFECTING FOOD. 



The fungi affecting food may broadly be divided into 

 those which attack the plant during its life (parasites), 

 and those which occur after its death (saprophytes). A 

 further division is into animal and vegetable parasites. 



These organisms destroy the fodder or grain on which 

 they live. Erom an agricultural point of view the para- 

 sites or those which affect the plant during its life are more 

 serious than the saprophytes which attack the crop after 

 it is gathered. From a veterinary point of view there is 

 little to choose between them ; both may be equally 

 harmful, not necessarily to the animal but to the food, 

 which is either partly or completely destroyed. In many 

 cases not only is the food rendered uneatable but positively 

 harmful. 



The principal Vegetable Parasites affecting the plant during 

 its life are Bunt, Smut, Rust and Mildew, and Ergot, while 

 those attacking the plant after its death produce mouldiness 

 and belong to the Mucor, Penicillium, and As2:)ergillus groups. 



Bunt is a parasitic disease due to Tilletia caries ; it affects 

 wheat, barley, and maize. It is a disease very difficult to 

 detect in the early stage, and requires carefully looking for. 



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