FEEDING OF THE OX. 547 



of the horse is to select food in such quantity and of such quality 

 as shall best promote, maintain, and repair the full energies of 

 health and strength. Even when a defined course of feeding 

 is known to supply all the materials contained in his entire 

 frame, a change is from time to time expedient. The useful- 

 ness of a variety of food is most probably dependent on the 

 simple substances essential to the due composition of the frame 

 being extracted more easily in the series of digestive processes 

 from one article of food than from another, though to appear- 

 ance equally accessible in both. 



The first thing to be ascertained in respect to any proposed 

 article of food is that it is a flesh-former, and not a mere sup- 

 porter of animal heat ; the next, that it contains such mineral 

 materials, or so-called mineral materials, as, being continually 

 thrown off by the excretions, are manifestly derived from the 

 disintegration of the animal solids, which require, therefore, to 

 be continually recruited by a new supply of the same. 



Application of Theory to the Feeding of the Ox. The type of 

 food for the ox already cited from Playfair (p. 508) was that of an 

 ox employed in field-labour a practice now almost, if not alto- 

 gether, extinct in this country. Nevertheless, it may be worth 

 while to exhibit the several orders of constituents contained in 

 that type of the daily food of a labouring ox. It consists of 

 50 Ib. of mangold- wurzel, 3 Ib. of beans, and 17 Ib. of wheat en 

 straw. The roots of man gold- wurzel contain, dried, 76.7 per 

 cent of heat and. fat giving proximate principles, chiefly sugar, 

 3 per cent of flesh-formers, and 9.56 per cent of mineral mat- 

 ter in the ash, thus 



100 : 76.7 : : (50 Ib.) 800 oz. : 613 oz. heat-givers. 

 100 : 3 : : 800 oz. : 24 oz. flesh-formers. 

 100 : 9.56 : : 800 oz. : 76 oz. mineral matters. 



Wheat-straw contains 36.7 per cent of heat and fat givers, 





