502 ANNUAL REPORT OF THE Off. Doc. 



For inslnneo, one hundred jtonnds of corn meal is given 41 per 

 cent, net; that is 58 ])er cent, is lost, or required lor digestion. When 

 we get to tiniolhy hay, 51 per cent, is re(iuired, leaving only 49 per 

 cent, for ])roduction, wheat straw, only one-fifth of all the energy 

 available for milk production. Tliat means that corn meal has only 

 four times as mudi energy as wheat straw. These figures exj>lain why 

 it is that our new standard is a more accurate measure of net energy, 

 than is our old standard. 



Now when we come to figure out a ration for the animals, we know 

 from practical experience and experiments that have been performed, 

 that every animal requires a certain amount of energy for lier main- 

 tainance; that is a dry cow, that is not in calf requires a sufficient 

 amount of food to keei) up her strength. That is what we si)eak of 

 as maintenance, therefore, we must give that cow enough feed to 

 take care of herself. The amount of feed she requires more than that 

 is for the milk she produces. A lot of us have lost money in times 

 gone by, because we didn't feed a cow more than she needed for her 

 own use. To put it in practical terms, suppose she needs six therms 

 (or we can call them units if you wish) of net energy to keep her- 

 self, if she is going to produce twenty pounds of milk, she will re- 

 quire another six therms, which is twelve; and if you only feed her 

 nine of them, you cannot expect her to produce twenty pounds of 

 milk In fact, she won't do so. AVhy? Because you haven't given 

 her strength enough to take care of herself and of her milk. 



You can take that milk to tlie laboratory and find just how much 

 energy there is in that milk. Let mo emphasize that statement in 

 this way. The amount of milk a cow gives is measured by her ability 

 to eat food above that required for her maintenance When you go 

 through the country and see a cow running thin, you may be sure 

 she was not fed enough to keep up her energy and produce milk. 

 The dairy cow is primarily a mother, and she makes milk to feed 

 her young. As soon as you see her getting fat, you have proof con- 

 clusive that she is getting more feed than she needs to produce milk. 

 There are thousands of farmers in this State who are losing money 

 because they do not feed enough to produce milk There are a few 

 farmers who go to the other extreme. But that is not the only thing 

 we can get energy from ; coal produces energy but the coav cannot 

 use coal so we must feed her something that she can eaf and digest — 

 something that she likes. So we feed he.r carbo-hydrates and fats to 

 produce milk. One hundred pounds of milk contains a little less 

 than sixty-four pounds of casein, and casein contains nitrogen which 

 comes only from carbo-hydrates; therefore we must supply protein 

 in sufficient quantities to produce the milk. If a mason begins a 

 foundation without enough brick of any kind, he cannot complete 

 it, because he cannot make mud take the place of brick; but if be 

 needs only one or two bricks, he can make mud take the place of 

 them. You cannot get a good milk production with an insufficient 

 supply of protein. It is true that when a cow is just fresh, in the 

 first month or month and a half of her period of lactation, if you 

 feed her an insufficient supply of the milk producing feeds, nature 

 has constituted her that she will take the fat from her own body 

 and make milk. That is why a cow gets thin after freshening. 

 Dairymen have profited by that. The Missouri Experiment Station 



