74 BUTTER-MAKING. 



and they are drawn out only when the last milk is removed. 

 (3) The fore-milk has been subjected to a re-absorption process 

 of the lymphatics. The third factor perhaps plays only a 

 small part in reducing the fat-content of the fore-milk. As 

 the fore-milk contains so very little fat, and a great many 

 micro-organisms, it is often advantageous to reject the first 

 few streams of milk. Especially is this important when sani- 

 tary milk is desired. 



It is in many instances customary, in order to apportion 

 the calf a certain amount of milk, to first partly milk the cow 

 by hand, and send this milk to the creamery, and then allow 

 the calf to suck the remainder. The results of such procedure 

 are plain, yet it is practiced to a large extent. When dis- 

 covered, it has in many instances explained why a certain 

 creamery patron's milk has been testing low at the creamery. 



Age of Cow. — There is a time during the life of a cow when 

 she is most vigorous and most productive. At the time she 

 first calves (abdtit three years old) the cow or heifer is still 

 growing, and her milk-proclucing" capacity is not so great then 

 as it is later on, when she becomes matured. After this increase 

 in quantity there is also a slight increase in quality. At the 

 age of about seven years the cow is usually at her best. As 

 the cow advances in age, usually the quantity and quality 

 diminish. However, the individuality of cows prevents draw- 

 ing any definite line. In some cows age has considerable 

 effect, while in others age has but little effect. 



Lactation Period. — By lactation period we understand the 

 milking period, from the time of calving until the cow is dried 

 up. The first few days after calving, the cow yields milk 

 which is rich in solids, not fat. The fat-content in milk from 

 most cows usually increases a trifle during the first two weeks 

 after parturition. Then, when conditions are normal and imi- 

 form, the percentage of fat is nearly constant for about three 

 months. After this time the quantity decreases and the 

 quality gradually increases a trifle. This applies more fully 

 if the cow is pregnant. Most cows calve in the spring of the 



