112 INVESTIGATION IN MILK PRODUCTION. 
If the nutrients required or a given flow of milk are provid- 
ed for in the concentrates the food of maintenance may be 
secured by feeding at least a portion of the roughage ad lib. 
If the grain mixture has a nutrive ratio of 1 to 5 or 5.5 it 
will fairly meet the requirements. 
In adjusting rations for cows fresh in milk note should 
be taken of surplus nutriment stored in the body during the 
time that a cow goes dry. If she gained rapidly in weight 
and is well rounded out with fat she will be able to do nor- 
mal work during the first few weeks of her lactation on a 
light grain ration, for she will use the stored fat in generat- 
ing body heat and energy and may also use some in the 
elaboration of milksolids. So as this milking-down in body 
weight takes place the concentrates should be gradually in- 
creased sothat she will be on full feed by the time she reaches 
her normal working weight. From then on the amount of 
concentrates should be as constant as the flow of milk will 
permit until after the sixth month of gestation when it 
should be gradually decreased so she will go dry during the 
seventh, when a couple of pounds a day will suffice. 
The deduction from the data indicates that the Wolft 
feeeding standard for dairy cows is fairly correct in the aver- 
age amount of total nutriment required. but faulty in that it 
prescribes an excess of protein and in the assumption that 
cows need nutrients in proportion to their weight. 
That the Wolff-Lehmann standard is faulty in that it 
prescribes an excess of protein and other nutrients; does not 
designate the nutrients required upon a basis of a unit in 
weight of milk; does not recognize the fact that quality of 
milk yielded should be considered as well as quantity, nor, 
that heifers require more nutrients for a given flow of milk 
than mature cows. 
That the nutrient requirements in milk production depend: 
1st.—Upon the weight of the cow. 
2nd.—Upon the quantity of milk yielded. 
3rd.—Upon the quality of the milk, and 
4th.—Upon the age of the cow. 
