FIFTIETH ANNUAL CONVENTION 79 



the inorganic form of phosphate of calcium. Contrary to 

 the earlier opinions, numerous experiments have shown that 

 animals can assimilate and use these inorganic phosphates 

 just as well as phosphorus in the organic compounds. 



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 precipitated calcium carbonate, 

 finely ground limestone, wood ashes, or chalk. Both cal- 

 cium and phosphorus are supplied by steamed bone meal, 

 bone flour, bone black, precipitated bone, or even ground 

 rock phosphate, tho the latter is probably less soluble in 

 the digestive tract than the other forms. When animals 

 are allowed to help themselves to the mineral supplement, 

 it is best to use one of the phosphates, for they are usually 

 more palatable than the carbonates, such as ground lime- 

 stone, and also they may be eaten in much greater quan- 

 tity without causing any disturbance in digestion. In sup- 

 plying a mineral supplement, it is a good plan to mix the 

 supplement with the concentrates. The use of expensive 

 proprietary mineral mixtures is unnecessary and generally 

 uneconomical. 



Common Salt. 



In spite of the well-known hunger of herbivorous ani- 

 mals for salt, practical men have differed as to the neces- 

 sity or advantage of adding it to the ration. It is now 

 agreed, however, that salt should be supplied regularly to 

 farm animals. It not only serves as a spice to whet appetite 

 and add to the palatability of many feeds, but it also stim- 

 ulates the digestive glands and prevents digestive disturb- 

 ances. 



At least for cows in milk, a supply of salt in addition to 

 that contained in the feed is absolutely necessary for health. 

 This was shown in experiments by Babcock and Carlyle at 

 at Wisconsin Experiment Station in which dairy cows, well 



