146 FEEDS AND FEEDING 



After an economical ration has been computed in this manner for the 

 average cow in the herd, it is not necessary to work out a ration 

 similarly for the other cows in the herd which differ in live weight 

 and milk production from this average cow. All that is needed is to 

 modify this ration according to the thumb rules given elsewhere in this 

 volume. (167, 647) 



195. Purchasing concentrates on the basis of net cost On most farms 

 in the United States the maintenance of soil fertility is an important 

 problem, and one always to be considered in the purchase of feeds. It 

 is pointed out in Chapter XVII that in determining which concentrates 

 are really the most economical to buy, the manurial value of the feed per 

 ton should be deducted from the actual cost. This manurial value is the 

 fertilizing value actually returned to the soil by applying the manure 

 produced thru feeding a ton of the feed. (437) It is there shown that 

 quite commonly in the corn belt and many other sections of the country 

 when credit is given for their high manurial value, the net cost per ton 

 of such protein-rich concentrates as cottonseed meal is actually lower 

 than the net cost of carbonaceous concentrates, including the farm-grown 

 grains. Under such conditions, even without taking into account their 

 high feeding value as supplements to farm-raised feeds, but merely 

 crediting them with their manurial values, they are really the cheapest 

 concentrates which can be used. They are far from being "high-priced 

 purchased feeds, ' ' as they are often termed by those who do not realize 

 their dual value as both protein-rich supplements and later as fertilizers. 



196. A cotton-belt ration for milk production. Let us next use the 

 method which has just been illustrated to determine the most economi- 

 cal ration for the same cow if owned by a southern dairyman who has 

 plenty of cowpea hay, worth $15 a ton, and corn silage, worth $5 a ton, 

 for roughage. Ground corn is worth $38 per ton, and ground oats, 

 $42 per ton. He can purchase choice cottonseed meal at $33 per ton, 

 wheat bran at $35, velvet bean feed (crushed velvet beans and pods 

 combined) at $33, and cottonseed hulls at $14 a ton. 



At these prices, it will be found that cottonseed meal furnishes total 

 digestible nutrients at 2.11 cents per pound, which is less than in the 

 case of any of the other concentrates available. Velvet bean feed comes 

 next, supplying total digestible nutrients at 2.19 cents per pound. The 

 cost in corn is 2.22 cents, in oats 2.98 cents, and in wheat bran 2.87 

 cents. Thus, under these conditions, cottonseed meal and velvet bean 

 feed, which are both rich in protein, furnish total digestible nutrients 

 more cheaply than the carbonaceous feeds corn and oats. 



The larger the proportion of cottonseed meal or velvet bean feed which 

 is used in the concentrate mixture for the cows, the cheaper will be the 

 ration. The conditions are therefore just opposite to the case of the 

 corn-belt dairyman, for with feeds at his prices, a ration high in protein 

 was more expensive, tho more efficient, than an unbalanced one low in 

 protein. Under such conditions as those of this southern dairyman, it 



