118 FEEDS AND FEEDING 



This may have been due to the unbalanced nature of the proteins of the 

 wheat grain, and perhaps also to the fact that the germs of the wheat 

 grain contain a substance which is somewhat poisonous when wheat is 

 fed in large quantities in such restricted rations as these, tho in the 

 amounts and combinations in which wheat and wheat by-products are 

 usually fed there is no trouble from this substance. 



These experiments emphasize the fact that in forming rations, we 

 must consider not only the physiological action of the individual feeds, 

 but also the effect of the combination as it is found in the ration. With 

 this in view the practical feeder and the student alike will attach especial 

 importance to the summaries presented in Part III of the results actually 

 secured with all classes of animals when fed many different rations. 



167. Hints on formulating rations. In computing rations one should 

 have in mind the approximate amounts of roughage and concentrates re- 

 quired per 100 Ibs. live weight by the various classes of animals. As 

 will be shown in the experiments reviewed in Part III, the proportion 

 of concentrates and roughages depends first of all on how much it is 

 desired to force the animal; for example, when it is desired to fatten 

 animals rapidly the allowance of concentrates must be considerably 

 larger than when they are fattened more slowly and over a longer 

 period. In a similar manner, the horse at hard work should be given 

 more grain and less roughage than the horse working but little. In 

 general, the following will be helpful as a guide in computing rations: 



Mature idle horses and mature cattle and sheep being maintained at constant weight 

 may be fed chiefly or entirely on roughage, unless it is of poor quality, when some grain 

 must be used. 



Horses at work should be fed 2 to 2.5 Ibs. of feed, (dry roughages and concentrates 

 combined) daily per 100 Ibs. live weight, the allowance of concentrates ranging from 

 0.7 to 1.4 Ibs. per 100 Ibs. live weight, for horses at medium to hard work. (See 

 Article 530.) 



Dairy cows in milk will eat 2 Ibs. of good quality dry roughage daily per 100 Ibs. 

 live weight. Silage may be*substituted for dry roughage at the rate of 3 Ibs. silage for 

 1 Ib. dry roughage. A common rule is to feed 1 Ib. hay and 3 Ibs. silage daily per 100 

 Ibs. live weight. Sufficient concentrates should be fed in addition to bring the nutrients 

 up to the standard. (See Article 647.) 



Fattening steers should receive 2. 1 Ibs. or more of concentrates and dry roughage 

 (or the equivalent in silage) daily per 100 Ibs. live weight, the allowance of concentrates 

 ranging from less than 1 Ib. to 1.7 Ibs. or more, per 100 Ibs. live weight, depending on 

 the rate of gain desired and the character of the roughage. 



Fattening lambs will consume about 1 . 4 Ibs. of dry roughage daily when fed all the 

 grain they will eat, and up to 2.3 Ibs. or over when the grain allowance is restricted. 

 Silage may replace a corresponding amount of dry matter in dry roughage. 



Swine can make but limited use of dry roughage, except in the case of brood sows not 

 suckling young. 



168. Maintenance ration for steers. Having discussed the general 

 factors which should be considered in computing rations for farm ani- 

 mals, let us now calculate the feed required, according to the Wolff- 

 Lehmann standard, to maintain a 1,000-lb. ox at rest in his stall when 

 neither gaining nor losing in weight. Since it has been shown that 

 mature animals can be maintained largely on roughages (90), let us see 

 how nearly field-cured corn stover and oat straw will meet the require- 



