70 



THE SCIENTIFIC FEEDING OF ANIMALS 



use in chronic constipation and in conjunction with less digestible and 

 constipating feeds. Fed to excess, they are apt to cause colic, diarrhea 

 and even gastroenteritis. The cause of the latter is not clearly under- 

 stood but is supposedly an acrid substance, acrin. In the course of time 

 animals may be accustomed to consume comparatively large quantities, 

 but in some cases this is done at the expense of digestive power. In 

 cattle excessive feeding on potatoes may lead to eczema of the hind quar- 

 ters (slop eczema) and inflammation of the prepuce in males (also in 

 sheep), and horses become subject to collar and saddle boils, eczemas 

 and colic. Prolonged feeding of potatoes is especially contra-indicated 

 for sheep, in which anemic and hydremic conditions may develop. 



Immature and sprouted potatoes, even when cooked, have a toxic 

 effect. The poisonous action is ascribed to the glycosid solanin and the 

 less toxic solanidin which is derived from it The solanin content of 

 potatoes grown in moist sandy soil is 0.011 per cent; dry sandy soil. 



a b 



l*"ig. 33. Section of Potato Tuber, a. Epidermis cells; c, starch filled cells. 



0.013 per cent; soil rich in humus, 0.0076 per cent; moist soil rich in 

 humus, 0.0045 per cent; while potato sprouts contain 0.476 per cent. 

 When it is considered that cattle frequently consume 50 pounds of pota- 

 toes or more per day, and swine 20 pounds, it is obvious that they may 

 ingest with this material 8 and 3 grams, respectively, of solanin, a quan- 

 tity of poison that may well produce the poisonings referred to. Horses 

 are less resistant to the effects of this poison than swine. 



The symptoms following the ingestion of sprouted potatoes, or of solanin pois- 

 oning, are extreme muscular weakness and even complete paralysis, comatose con- 

 ditions, inflammation of the brain (sheep) and even death (from exhautsion of 

 respiratory muscles). When fed exclusively, or with insufficient other feed, 

 potatoes and potato peelings, which are poor in lime salts, cause halisteresis ossium 

 (softening, etc., of the bones) in cattle, goats and swine. Cows fed excessively 

 on potatoes produce milk and cream that are hard to churn. The butter is salvy 

 (Henry and Morrison). 



