158 THE CHEMISTRY OF CATTLE FEEDING 



for 40 per cent, of it [i8'8 X 0^40] = 7*52 Ibs. is consumed in 

 the work of digestion ; this energy appears as heat, and helps 

 to maintain the temperature of the animal's body; 7*52 Ibs. 

 may, therefore, be deducted from the original maintenance 

 ration, and the 18*8 Ibs. required for work is to be added to 

 the difference. The total amount of hay required, therefore, 

 is 19'! 7*52 + 18*8 = 30-38 Ibs. 



The last example is intended merely to illustrate the method 

 of investigation. A horse of 1000 Ibs. live weight would 

 probably experience no difficulty in consuming and digesting 

 30 Ibs. of hay per day, but it does not follow that such a ration 

 would enable it to do the specified amount of work in the 

 given time. Not only is hay difficult to digest, but the process 

 is a slow one, and the animal cannot therefore put forth the 

 effort rapidly. It is a matter of practical experience that 

 horses are sluggish and cannot work fast when fed entirely 

 upon hay. When they are required to work rapidly, the 

 additional food (for work) should be of a readily digestible 

 character. It is found that, for some reason, oats are the best, 

 but this food may be wholly or partially replaced by mixtures 

 of maize, beans, etc., without obvious disadvantage. A ration 

 consisting entirely of hay would be more suitable for oxen 

 than for horses, because these animals are better able to digest 

 such materials, and also because, in any case, they work at a 

 slower rate. Even oxen, however, work much better when fed 

 on rations consisting partly of corn. The difference is, perhaps, 

 more correctly stated by saying that in the case of oxen a larger 

 proportion of the ration may consist of hay. 



It will be noticed that the sluggishness of horses when fed 

 entirely upon hay is attributed to the fact that this food takes 

 a long time to digest, and not to a deficiency of nutrients in it. 

 Matters are not, therefore, improved in this respect by giving 

 larger quantities of the coarse fodder instead of the more 

 readily digestible corn. 



A similar phenomenon is noticed in regard to fattening 

 animals. They may improve up to a certain point, but never 

 grow really fat on rations of coarse fodder, however much they 

 receive. For the same reason grazing animals do not fatten 



