TUBERS AND ROOT CROPS 69 



ity. They have no value as feeding stuffs but are too frequently found 

 as adulterants in prepared commercial "meals." 



The hulls of Leguminosae are rich in protein and are in every respect 

 equal to good meadow hay in feed value. On the other hand the hulls 

 of buckwheat, mustard, flax, false flax and rape (!) are very inferior 

 and might be compared with winter cereal straw in feeding value. The 

 digestible protein content of chaff" varies between 0.5 per cent in barley 

 and 1.4 per cent in oats, while the starch value varies between 22 per 

 cent in rye and 28 per cent in oats. The digestible protein and starch 

 values of the hulls are 3.5 and 20 per cent respectively. 



The various kinds of chaff are fed principally to cattle and swine, 

 much more rarely to horses as a substitute for "chaffed straw." The 

 dust particles should first be removed by screening. Chaff should be wet 

 and scalded before feeding to horses, steamed or fermented for cattle 

 and swine (cf. p. 29). The hulls of lupines, beans, rape, and turnips are 

 usually fed to sheep in the dry state. 



Pea hulls have a high dietetic value for swine suffering from chronic 

 constipation (^^ to 1 pound daily). Buckwheat hulls when properly pre- 

 pared are also valuable for swine, but are said to be liable to cause con- 

 stipation in horses, which is true also of spelt chaff. 



Great care should be taken in the feeding of any kind of chaff. This 

 feeding stuff is frequently contaminated with parasitic fungi, the seeds 

 of weeds (frequently of a poisonous nature, as cockle seed), etc. As a 

 rule chaff' should be used as a supplementary feed only. 



III. Tubers and Root Crops 



Tubers and root crops include potatoes, artichokes, turnips and beets, 

 carrots, etc. All root crops are rich in water and carbohydrates, poor in 

 protein, and poor in lime and crude fiber. Phosphates are present in 

 moderate amount. The digestible protein content is about 0.2 per cent, 

 and the starch value of the potato, according to water content, 13 to 20 

 jier cent ; mangel-wurzel, 5 to 7 ."b per cent ; sugar beet and artichoke, 

 15.5 per cent; carrots, %.7 per cent. They are important, easily digesti- 

 ble feeding stuffs for cattle and swine, but, on account of their deficient 

 protein content, not adapted for complete rations. When fed to rumi- 

 nants" the addition of dry roughage is absolutely necessary-. 



1. Potatoes 



Solanum tuberosum is the original source of the many varieties. Fig. 

 33 represents a cross section through a potato tuber. The carbohydrates 

 are present in the potato principally in the form of starch. The more 

 nitrogenous, glassy, soapy varieties of potatoes are preferred as stock 

 feed, while the mealy sorts which are more starchy are preferred for 

 table use, for starch manufacture and for the manufacture of alcohol. 



Advantages and disadvantages of potato feeding. Fed in moderation, 

 raw potatoes stimulate digestion and have a laxative effect, hence their 



