FEED AND CARE OF THE DAIRY COW 401 



5. Ground barley 410 Ibs. 6. Hominy feed 175 Ibs. 



Linseed meal 390 Ibs. Ground barley 200 Ibs. 



Wheat bran 200 Ibs. Linseed meal 400 Ibs. 



In 1 Ib. : Wheat bran 225 Ibs. 



Dig. cr. protein, 0.180 Ib. In 1 Ib. : 



Total dig. nutr., 0.751 Ib. Dig. cr. protein, 0.179 Ib. 



Total dig. nutr., 0.755 Ib. 



651. Computing rations, using suggested concentrate mixtures. To il- 

 lustrate the way in which these suggested concentrate mixtures should 

 be used in computing a ration for a given herd of cows, let us suppose 

 that the cows in a certain farmer's herd average 900 Ibs. in weight and 

 are yielding on the average 20 Ibs. of 5 per ct. milk daily. He is feed- 

 ing good red clover hay and corn silage for roughage, approximately 

 at the rate of 1 Ib. of hay and 3 Ibs. of silage per 100 Ibs. live weight. 

 After studying the prices of the available concentrates in the manner 

 described in Chapter VIII, he decides that the concentrate mixture 

 given under A-2 is the most economical for him to use; i.e., ground corn, 

 575 Ibs. ; choice cottonseed meal, 175 Ibs. ; and wheat bran, 250 Ibs. 



Let us then see if this mixture, combined with the roughage he is 

 feeding, will make a well-balanced ration. First we must compute 

 the requirements for a 900-lb. cow yielding daily 20 Ibs. of 5 per ct. 

 milk. Her requirements, according to the Morrison feeding standards, 

 will be found to be 1.830 to 2.090 Ibs. digestible crude protein and 14.372 

 to 15.172 Ibs. total digestible nutrients, as shown in the following table. 

 Then we must compute the digestible crude protein and total digestible 

 nutrients in 9 Ibs. of red clover hay and 27 Ibs. of corn silage. The 

 roughage will furnish 9.360 Ibs. of total digestible nutrients, as shown 

 in the table. Subtracting 9.360 Ibs. from 15.172 Ibs., the higher amount 

 of total digestible nutrients advised in the standard, leaves 5.812 Ibs. 

 total digestible nutrients, which must be supplied in the concentrate 

 mixture. Since 1 Ib. of the concentrate mixture supplies 0.782 Ib. total 

 digestible nutrients, it will take 7.5 Ibs. to meet the requirement. This 

 will supply the nutrients shown in the table. (If concentrates were 

 very high in price compared with roughages, it might be more economical 

 to feed only enough concentrates to bring the total digestible nutrients 

 to the lower figure in the standard; i.e., 14.372 Ibs.) 



Ration for 900-lb. cow yielding 20 Ibs. of 5 per ct. milk 



Digestible Total 



crude digestible Nutritive 



protein nutrients ratio 



Lbs. Lbs. 



Requirements for above cow 1.8302.090 14.37215.172 



Trial ration 



Red clover hay, 9.0 Ibs 0.684 



Corn silage, 27.0 Ibs 0.297 



Total in roughage 



Concentrate mixture, 7.5 Ibs 



Total 2.023 15.225 1:6.5 



