236 WINTER FEEDING OF DAIRY COWS 



to Table II, under the section headed " Percentage of fat in 

 milk 4.2/' we may easily calculate the amount of each nutrient 

 by taking the amount indicated for 2 pounds of milk and mul- 

 tiplying by 10 and then adding in the amount needed for 

 pounds of milk. Thus we find that for the formation of 20 

 pounds of 4.2 per cent milk there are required 1.44 pounds of 

 digestible protein, 6.5 pounds digestible carbohydrates and 0.50 

 pound digestible fat. Adding the two amounts we have : 



From the above we see that the cow assumed must be pro- 

 vided with 2I4 pounds protein, ll 1 ^ pounds carbohydrates and 

 more than l/o pound fat per day or she will either decrease in 

 milk flow or lose weight, or do both. 



To supply the nutriment required suppose we feed : 



Lbs. Protein Carbohydrates Fat 



Timothy hay 12 .336 5.21 .168 



Corn silage 36 .345 5.15 .252 



Corn 5 .395 3.33 .215 



Oats 4 .428 2.01 .152 



Nutrients provided 1.504 15.70 .787 



Nutrients required 2.245 14.55 .67 



It will be noted from the above example that, although the 

 regulation amounts of hay, silage and grain have been fed, and 

 that carbohydrates and fat amounts are well provided, pro- 

 tein is 0.74 pound short. This ration is balanced in respect to 

 roughage to cow and grain to milk, but far from it in the more 

 vital part, digestible nutrients, especially protein. Reference 

 to table of analysis shows that cottonseed meal, linseed oil meal, 

 gluten feed and bran are richer in protein than corn or oats. 

 To correct the balance of nutrients and to keep the number of 

 pounds the same, suppose we try the following: 



