CALCULATION OF RATIONS 77 
There are several other considerations that should receive atten- 
tion in formulating rations for farm animals, besides supplying 
nutrients in the right amounts and proportions and getting an effec- 
tive ration at as low a cost as possible. Among these are: 
First, the feeds must be palatable to the animals fed and must 
not have any deleterious influence on their digestion or general health 
or on the products which they furnish. A well-balanced ration for 
milch cows can be made up of oat straw and oil meal, but it would 
not be likely to produce satisfactory results, because of the large 
amount of roughage the cows would have to consume and the unpala- 
tability of the ration. 
Second, the rations must contain a fair proportion of roughage 
and concentrates ; they must not be too bulky and still must contain 
a sufficient amount of roughage to keep up the rumination of the 
animals, in the case of cows and sheep, and to secure a healthy 
condition of the animals generally. In the case of dairy cows, about 
. two pounds of hay are generally fed per hundredweight, if this is the 
sole roughage. If silage is available, one pound of hay and three 
pounds of silage may be fed per hundredweight, and one pound of 
concentrates for every three to five pounds of milk produced, accord- 
ing to the character of the roughage and tne quality of the milk pro- 
duced; if a good quality of roughage is available, less grain may be 
fed, and vice versa. Cows producing milk of low fat content should 
receive less grain per pound of milk than high testing cows (see 
p. 240). A good rule for feeding grain to cows on mixed hay, corn 
stover, corn silage, and similar low-protein roughage is to allow as 
many pounds of grain a day as the cow gives pounds of butter fat 
in a week. Cows receiving a good grade of alfalfa or other rich 
coarse feeds will not need more than one-half of this amount of 
grain feed. 
Third, the ration should conform to the system of farming fol- 
lowed, and this should be arranged with a view to growing on the 
farm, if possible, all the roughage and most of the concentrates which 
the stock are to receive, so that the farmer may be largely indepen- 
dent of the feed market with its fluctuating prices. 
Fourth, the rations are preferably composed of feeds of different 
origin, so that, especially, the protein substances are supplied from 
different sources. The recent experiments with cows fed rations 
balanced from restricted sources (corn, wheat, or oat products only) 
at the Wisconsin Experiment Station ? illustrate in a striking way 
the necessity of furnishing a variety in the make-up of rations for 
‘Research Bulletin 17, 
