FEEDING STANDARDS CALCULATING RATIONS 137 



190. Kation for fattening 2-yr.-old steers. To illustrate the manner of 

 computing rations in accordance with the Morrison standards, let us 

 formulate a ration for fattening 2-yr.-old feeder steers. The steers, 

 averaging 900 Ibs. when placed in the feed lot, are to be fed a heavy 

 fattening ration for 150 days so that they will gain 2.4 Ibs. per head 

 daily, or more. The Morrison standards for 2-yr.-old steers on full feed 

 are as follows: 



Morrison standards for 2-yr.-old steers on full feed (From Appendix 



Table V) 



It will be noted that the allowance of dry matter is the largest for the 

 first 40 to 60 days of fattening. During this period the steers are being 

 brought to a full feed of grain and are hence consuming a larger pro- 

 portion of roughage to concentrates than in the later periods. The 

 amount of total digestible nutrients required per 3,000 Ibs. live weight 

 also decreases as the steers fatten, but not so much as does the dry 

 matter. The minimum amount of digestible crude protein advised for the 

 first period is 1.9 to 2.2 Ibs. per 1,000 Ibs. live weight. The larger 

 amount will probably tend to slightly more rapid fattening than the 

 lower figure, but, as is pointed out later, may be less economical than 

 the lesser amount. (197) 



On comparing these standards, which are based on the results of 

 American feeding trials, with the original Wolff-Lehmann standards, it 

 is seen that the minimum allowance of digestible crude protein advised 

 is considerably lower than in the original standards. The dry matter 

 is also materially lower, for fattening steers fed roughage of good qual- 

 ity, as is commonly done in this country, will not consume as much dry 

 matter as set forth in the original Wolff-Lehmann standards. 



In computing rations for these steers, the most accurate way is to 

 figure out the rations on the basis of the average live weight of the steers 

 during each period of fattening. Jf the steers weigh 900 Ibs. when 

 placed on feed and gain 2.4 Ibs. per head daily, their average weight for 

 the first 50 days will be 1,020 Ibs.; for the second 50 days, 1,140 Ibs.; 

 and for the last 50 days, 1,260 Ibs. Computing the standard require- 

 ments for each period on this basis we have: 



