MAINTENANCE REQUIREMENTS OF MATTER 345 



Diakow 1 and Cochrane, 2 each on a single steer. Diakow's ex- 

 periments include four periods on mixed rations containing 

 much hay. In Cochrane's experiments alfalfa hay constituted 

 the sole feed, supermaintenance, maintenance and submain- 

 tenance rations being consumed. Accordingly, the total ration 

 contained in every instance a considerable excess of bases. 

 Under those conditions, not only the feces but likewise the 

 urine showed an excess of bases over acids, i.e., the animal 

 was engaged in getting rid of excess bases. The net residue 

 which was retained in the body consisted of basic material of 

 rather constant composition even in the case of Diakow's nearly 

 mature animal. 



So far as they go, then, these experiments confirm the con- 

 clusion that with rations containing a large proportion of 

 roughage, there is no reason to fear losses either specifically of 

 fixed bases or in general of total ash. Such would almost always 

 be the case with the ordinary maintenance rations of cattle, 

 sheep and horses. Swine, on the other hand, if maintained 

 entirely on grain, might very well receive rations not well 

 balanced as regards ash, and experiments and observations 

 which are discussed in Chapter XI (492-496) seem to indicate 

 that even for maintenance the ordinary grain ration, especially 

 if it consists largely of maize, should have its ash composition 

 corrected. The effect of an acid ash in the mixed rations of 

 herbivora, and the extent to which such acidity can be taken 

 care of in the body without drawing on its reserves of ash, has 

 still to be investigated. In view of the large amounts of surplus 

 bases excreted under the conditions of Diakow's and Cochrane's 

 experiments, it would seem likely that even a considerable 

 excess of acid elements might be neutralized without drawing 

 on the stock of fixed bases in the body. 



In Diakow's experiments, the minimum quantities of 0.115 

 Ib. calcium and 0.045 lb. phosphorus in the feed per 1000 pounds 

 live weight sufficed to support not inconsiderable gains by the 

 body. In Cochrane's experiments, a minimum of 0.147 Ib. cal- 

 cium per 1000 pounds also resulted in a gain, while 0.039 Ib. 

 phosphorus was just sufficient for maintenance. In Henneberg's 

 investigations 3 upon the maintenance of cattle, however, dis- 



1 Landw. Jahrb., 44 (1913), 833. 2 Penna. Inst. of An. Nutr., unpublished results. 

 1 Beitrage, etc., Heft, 1 (1860), p. 113. 



