ROOTS, TUBERS, AND OTHER SUCCULENT FEEDS 143 



yield of 100 bushels to the acre. The Alabama station 13 showed as the average 

 of two trials that chufa will produce pork at the rate of 307 pounds per acre, 

 after allowance was made for the grain feed eaten, while in trials at the 

 Arkansas station an. acre of chufa produced 592 pounds, against 1252 

 pounds from an acre of peanuts and 436 pounds from an acre of corn. 14 



The sweet potato (Ipomcea, batatas) is another southern crop that 

 grows as far north as Illinois, Kansas, and New Jersey. Its greatest im- 

 portance is as a human food, but, in the absence of good near-by markets and 

 proper transportation facilities, it becomes of considerable value as a feed for 

 stock, especially swine, in regions adapted to its culture. Fed sliced, they 

 make a good cattle and horse, feed. Pigs do their own harvesting. Three 

 pounds of sweet potatoes contain nearly as much dry matter, quite as much 

 carbohydrates, and less than one-half as much protein as are generally con- 

 tained in one pound of Indian corn. 15 By using one-half pound cotton-seed 

 meal, or one pound cowpeas for every ten pounds of sweet potatoes, the de- 

 ficiency in protein will be fully covered. The Florida station 10 found that 

 sweet potatoes can replace one-half of the corn in rations for work horses, 

 the feeds being substituted in the ratio of three to one. Trials with dairy 

 cows at the same station indicate that 100 pounds of sweet potatoes have a 

 nutritive effect similar to 150 pounds of corn silage. Sweet potatoes con- 

 tain, on the average, 31.7 per cent water, 1.1 per cent ash, 1.9 per cent pro- 

 tein, 26.8 per cent carbohydrates, and 0.7 per cent fat. Their high sugar 

 and starch contents (4 to 6 per cent and 16 to 18 per cent, respectively) 

 render them especially valuable as a feed for fattening swine. 



Sweet potato vines are also utilized as a feed for cattle. They may be 

 considered similar to cowpea vines in feeding value, and are better suited for 

 feeding green than for curing into hay or for silage. 



Sweet Cassava (Manihot aipi) . This is a sub-tropical plant belong- 

 ing to the milk-weed family, which is cultivated for its starchy roots. These 

 are used for the manufacture of starch and for stock feeding. Ninety-five 

 per cent of the cassava grown in this country is fed to livestock ; all classes 

 of farm animals eat it with a relish and thrive on it better than when con- 

 fined to only dry feeding. 17 Cassava is grown in the Gulf States in this 

 country, and cannot be grown outside of an area extending 100 miles from 

 the coast of the Gulf States, and possibly South Carolina. Five to six tons 

 of roots per acre are a fair crop. The following analysis shews the com- 

 position of cassava roots: 



66.0 per cent moisture, 0.7 per cent ash; 1.1 per cent protein, 1.8 

 per cent fiber, 30.2 per cent nitrogen-free extract, 0.2 per cent fat; nutritive 

 ratio, 1 : 28.5. 



On account of its wide nutritive ratio cassava is best supplemented with 

 high-protein feeds common in the South, like cowpeas, velvet beans, cotton- 

 seed meal, etc., in feeding growing animals, milch cows, or fattening stock. 

 It furnishes an excellent substitute for winter pasture as well as* for 

 silage where a farmer does not keep a sufficient number of animals to make 

 the investment in a silo profitable. Unlike the roots of cassava varieties 

 grown in the tropics, sweet-cassava roots contain only traces of prussic acid. 



Apples and other fruits are at times available for stock feeding 

 in orchard regions during the sum.mer and fall and may be fed with 



"Bulletin 122. 



14 Bulletin 54 ; see also Farmers' Bulletin 102. 

 * 10 Farmers' Bulletins 26 and 129. 

 10 Bulletin 72. 

 "Farmers' Bulletin 167. 



