STUDIES IN MILK SECRETION. 



The University herd has consisted during the past several 

 years of about twenty cows, the most of which have been grade 

 Jerseys and grade Holsteins. In building up the herd the aim 

 has been to form one that would furnish an object lesson to those 

 farmers who desire to improve their herds but do not feel able to 

 purchase thoroughbred stock entirely. Accordingly the herd 

 has been developed from the ordinary stock of the neighborhood 

 by the use of thoroughbred bulls and a rigid selection of the 

 best heifers. This course of breeding was established by Pro- 

 fessor Roberts in 1875 and has been continued ever since In 

 1874 the average 3'ield of milk per cow was a little more than 

 3000 pounds. The descendants of these same cows, as will be 

 seen in the following pages, have produced an average of over 

 7,500 pounds during the year 189 7-' 98. This increase of two 

 and one-half times is the result of judicious selection of sire and 

 dam, together with careful feeding, and is a result which every 

 farmer can obtain by following a similar course. 



The general management of the herd is on the plan of a 

 winter dairy, i. e., the cows are bred, so far as possible, to 

 calve during the early fall months. They are milked about 

 ten months and most of them are dry during July and August. 

 In the summer they are at pasture which is supplemented 

 with corn or other green forage crops whenever the pasture 

 becomes dry or scanty. In the winter they are stabled at night 

 and during the day run in a covered j-ard which is well bedded 

 and where they have access to water, none being supplied in 

 the stable. The frontispiece shows the cows in the covered 

 yard mentioned. 



Since the introduction of the Babcock test a careful record 

 has been kept of the amount of butter-fat produced by the herd. 



Each cow's milk is weighed daily and once a week a sample of 

 an equal amount of nights and mornings milk is taken from 

 each cow. The fat in these samples of mixed milk is deter- 

 mined by the Babcock test and this percentage multiplied by 



