INORGANIC NUTRIENTS 157 



The percentage of other mineral matter utihzed (except oxid of iron, 

 which is 38 per cent) is less than 38 per cent of the amount consumed. 

 According to the results above tabulated, the lime consumed has been 

 so completely utilized that only 3 per cent of the amount consumed was 

 excreted. Since a small portion of every mineral substance that plays a 

 role in metabolism is excreted, even when entirely wanting in the feed 

 consumed, the small amount of lime (0.44 gm.) excreted can not be re- 

 garded as an excess in the feed supplied. On the contrary, the eager- 

 ness with which suckling calves consume lime-containing substances like 

 mortar, lime and chalk is an indication that they do not receive an ade- 

 quate supply in the milk and that the milk of our highly developed breeds 

 of cattle is deficient in this bone-forming mineral and that an additional 

 supply of lime in the form of precipitated chalk (15 gm. or Yz oz. daily) 

 is advisable. Such daily doses of lime would have the additional advan- 

 tage of assisting or furthering the utilization of the phosphoric acid in 

 the building up of the bones. 



Phosphoric acid and lime can usually be obtained on the market in 

 the form of calcium phosphate, under such names as phosphated feed 

 lime, bone feed meal, or precipitated calcium phosphate. Since lime and 

 phosphoric acid precipitate each other in the digestive tract when the 

 contents are alkaline in reaction and thus prevent absorption of either, 

 or at least hinder the process, it is best to administer them separately 

 and at different times. For example, the lime preparation (calcium 

 chlorid ^ oz.) (or prepared chalk up to from 3 to 6 ounces per day 

 for cattle) may be given daily for three successive days followed bj 

 some readily absorbable phosphate (sodium phosphate, tablespoonful 

 three times a day for cattle) for three days, then lime salts again for 

 three days, and so on, provided, of course, that the feed used is deficient 

 in both of these elements. If both are deficient, both must be provided 

 in this artificial manner. Since the proportion of lime to phosphoric 

 acid in the bones is a rather constant one (52-40), an excess of either 

 will not be used in the formation of bone tissue. As a matter of fact, 

 an excess of phosphoric acid has a distinct tendency to make the defi- 

 ciency in lime more pronounced than ever. In the feeding of large 

 amounts of concentrates like the grains and oil cakes, with slops, beets, 

 potatoes and straw, there is a deficiency of lime salts. This deficiency 

 can usually be corrected and ordinarily it suffices merely to add the latter 

 to the ration, but it is best to do this on the three-day interval plan. 

 Where liberal fertilizing with phosphates is practiced for crops, addi- 

 tion of these salts to the feed can usually be dispensed with. 



Lime in the form of prepared chalk is recommended with the feeding 

 of sweet pressed feed and with sour silage. The lime precipitates or 

 neutralizes the free acids and forms readily soluble compounds (lactate 



