MAINTENANCE OF FARM ANIMALS 67 



make a ration balanced according to the feeding standards, have 

 usually aborted or produced dead or weak offspring. When calcium has 

 been added to the ration in such forms as calcium phosphate or wood 

 ashes, the results have been greatly improved, but the calves have not 

 been as vigorous as where alfalfa or clover hay has formed part of the 

 roughage. Other roughages high in lime have likewise given satisfactory 

 results, including corn stover and even timothy hay and marsh hay, 

 which were higher in lime than is frequently the case, because they 

 had been grown on alkaline soil. From these experiments they advise 

 that rations for dry breeding cows contain at least 0.45 per ct. of lime 

 (calcium oxide), and preferably even a larger amount. 



In similar experiments with swine it was found that when brood sows 

 were restricted to a ration of grain and common salt, many of the pigs 

 produced were dead at birth, even tho the sows drank water which 

 contained considerable lime. When 15 to 25 per ct. of alfalfa hay was 

 added to the ration, normal living litters were produced. 



These trials show in a striking manner that in forming rations the 

 calcium content of feeds should be considered. Forage from the legumes 

 greatly excels all other farm-grown feeds in amount of calcium. Milk 

 and the dairy by-products, skim milk and buttermilk, are also very 

 rich in calcium. Tho containing much less than legume hay, the legume 

 seeds in general, and also cottonseed meal and linseed meal, are richer 

 than the cereal grains. Straw, root crops, molasses, and the cereals and 

 their by-products are low in calcium. 



Most of the common feeds which are rich in protein are also high 

 in phosphorus. Therefore, rations which contain sufficient protein to 

 meet the feeding standards will usually contain plenty of phosphorus. 

 The cereals and their protein-rich by-products are rich in phosphorus, 

 as are also the various oil meals and cakes, the slaughter-house and fish 

 wastes, and the leguminous roughages. On the other hand, straw, beet 

 pulp, potatoes, and molasses are low in this mineral constituent. 



Formerly it was believed that phosphorus in such organic compounds 

 in feeds as the proteins and the phosphorus-bearing fatty substances had 

 a higher nutritive value than phosphorus in such materials as ground 

 bone and ground rock phosphate, which contain phosphorus in the in- 

 organic form of phosphate of calcium. Contrary to the earlier opinions, 

 numerous experiments 14 have shown that animals can assimilate and use 

 these inorganic phosphates just as well as phosphorus in the organic 

 compounds. 



99. Mineral supplements. Whenever there is any danger that the feeds 

 given farm animals contain too little calcium or phosphorus for health 

 and maximum production, these mineral nutrients may be supplied 

 at little expense. Calcium alone may be furnished in the form of pre 



"Hart, McCollum and Fuller, Wis. Res., Bui. 1; Forbes, Ohio, Tech. Bui. 5; 

 Burnett, Nebr. Bui. 107; Kohler, Land. Vers. Stat, 61, 1C 05; 65, 1907; Neumann, 

 Jour. Landw., 41, 1893, p. 343. 



