MANUAL OF CATTLE-FEEDING. 4G7 



Suppose tliat there is available for tlxe daily fodder of 

 the cows, per 1,000 lbs. live- weight, twelve pounds of hay, 

 six pounds of oat straw, and twenty pounds of mangolds, 

 and that brewers' grains can be had cheaply. Plainly what 

 w^e have to do is, first, to ascertain how much digestible 

 matter the available amounts of coarse fodder and roots 

 will furnish, and second, to calculate how much must bo 

 added to this ration to bring it up to the feeding standard. 



We first need to know the percentages of digestible 

 protein, carbhydrates, and fat contained in each of the 

 feeding-stuffs, and for this purpose we must avail our- 

 selves of the results obtained by others, since it is obvious- 

 ly impracticable to make direct digestion experiments. 

 For this purpose we make use of tables of the composition 

 and digestibility of feeding-stuffs, like those given in the 

 Appendix, in which the results of all available analyses 

 and digestion experiments are condensed. 



The tables given in the Appendix are essentially those of 

 Julius Ivuhn ; they show both the amrage composition and 

 digestibility of the common feeding-stuffs and also the ob- 

 served range of variation in these respects. "Wolff, in his 

 table, gives directly the average percentage of digestible 

 nutrients contained in each fodder, thus facilitating the cal- 

 culation of rations. This convenience, however, is attained 

 only by assxmung a nnif orm composition and digestibility 

 for each feeding-stuff, assumptions which, as we have seen, 

 and as Kiihn's tables show, are far from being true, particu- 

 larly as regards coarse fodder. Moreover, comparatively few 

 feeding-stuffs have been tested as to their digestibility, that 

 of the others being only estimated. Under these circum- 

 stances the most rational method is to endeavor to form an 

 estimate in each particular case of the atnount of digestible 

 matter likely to be present in the fodder. This method, 



