274 ANNUAL REPORT' OF THE Off. I>oc. 



when the cows went to pasture, in some it changed in the opposite 

 direction. The average was practically no change. 



Yet every -dairyman knows that milk varies in its richness. If, 

 then, this is not due to the feed, what is the cause? Most of the varia- 

 tion is due to the changes in connection with the progress of the 

 period of lactation. Just after a cow calves^, the milk is the thin- 

 nest it is to be anvtime in the vear and it remains with but little 

 change in quality, until the cow gets in calf again. Then as the 

 quantity of milk gradually decreases the per cent, of fat slowly rises 

 and the milk is richest in fat just before the cow goes dry. The ex- 

 tent of the variation differs widely in different cows. In my own 

 experience I have had a cow that gave at first milk containing three 

 and a half per cent, of fat, and just before she went dry milk of four 

 and a half per cent, increasing only one per cent. Another cow just 

 doubled from three and a half to seven per cent., while still a third 

 cow on calving gave seven per cent, milk, and the last milking be- 

 fore she went dry tested over fourteen per cent, of fat — it was cream 

 rather than milk. 



Then, too, there is usually a variation between the quality of the 

 milk produced in the morning and in the evening. The rule is that 

 the richer milk is given at the milking that occurs after the shorter 

 number of hours between milkings. If the milking is done in the 

 winter at seven in the morning and five in the evening, the evening's 

 milk win be the richer for there are only ten hours between the 

 morning and evening milkings. In the summer when the hours of 

 milking are reversed, the morning's milk will be the richer. After 

 allowance has been made for all the above mentioned causes, there 

 is still a daily and weekly fluctuation in the richness of the milk due 

 to causes as yet unknown. But the fact of this variation is certain. 

 I have found it in single cows and in large herds, when there was no 

 assignable cause. I have isolated a fine healthy vigorous cow and 

 treated her with exceptional care and regularity and yet she has 

 varied a whole per cent, in the richness of her milk during a single 

 week. This phase of the subject needs to be made prominent be- 

 cause a lack of knowledge of the fact has led to many a wrangle and 

 much hard feeling at creameries that pay by test. Ilecause your 

 test one week is different from the week before, do not jump at once 

 to the conclusion that the creameryman has made a mistake or is 

 trying to cheat you. Either may be true, but the variation in the 

 test is not proof of either. 



The statement has been made that no change of feed will make 

 the milk richer. It is easy, however, to lessen the quality. Any ir- 

 regularity in the dally routine will be reflected in a smaller quantity 

 — a change in milkers or in the manner of milking, a change in the 

 time, place or order of milking — anything that is not expected or a 



