ILLINOIS DAIRYMEN'S ASSOCIATION. 137 



can test that cow for butterfat two or three times during that 

 period, but when it comes to talking of what she eats, that is a 

 different proposition. Yet it is a practical question, and a ques- 

 tion that will not give value to the other two, unless that is de- 

 termined.. 



In weighing the milk of a dairy cow, it is better to weigh 

 the milk of each milking during the period of lactation, not 

 necessary for practical purposes, however. If we weigh the milk 

 one day in a week, night and morning, pick out the same day in 

 the week, Thursday we will say, and weigh the milk again morn- 

 ing and night, and make a record, you will find out a close 

 approximate of the actual amount of milk she yields. If you 

 think this isn't so, you take the records of your experiment sta- 

 tion at the university, and select out Thursday, or any other day, 

 and multiply by seven and then get the total through, you will 

 get very close to the actual yield of the milk. Take any of them 

 and do the same thing. One clay in each week, for practical 

 purposes is all that is necessary to weigh the milk of a cow so 

 you can determine her real value as a producer. I know men 

 who weigh once in ten days, and it works very well. They 

 prefer to multiply by ten than seven. If you are afraid you will 

 forget the time, make out a table and hang it in the dairy stable, 

 and that tenth clay you weigh the milk. You will find out you 

 have a close record to pick out the poor cows from the good ones. 



In testing for butterfat, we can't test one milking of a cow 

 during a period of lactation and multiply the yield of the milk 

 produced in a year by that and select out our best cows, because 

 cows vary in the percent of fat. We have got to have an average 

 so we can make a proper estimate. In the early part of the period 

 of lactation, cows do not give quite as rich milk as they do later 

 on. During the latter portion of the period they give better milk. 

 At least test three times during period. Once when they are 

 fresh, once in the middle, and once towards its close. Cows vary 

 from one milking to the other, and we ought not to risk a sample 

 from a single milking. Have a composite sample. Take sam- 

 ples from four consecutive milkings for one composite sample 



