Studies in Milk Secretion. 53 



From such a mass of material it is difficult to glean the more 

 important points and place them in digestible form before the 

 general reader ; but we have attempted to draw out those points 

 that appear of most scientific and practical importance to the 

 student, breeder and dairyman, and to place them in as readable 

 form as possible. With so much data at hand it is natural to 

 make many tables, but we have endeavored to eliminate all such 

 as show figures mereh' and to present only those which teach 

 some lesson or from which some practical conclusion can be 

 drawn. 



All records contained in the following tables were made from 

 tests continuing for seven consecutive days. In these records 

 we have given the amount of pure 'butter fat produced but not 

 its equivalent in marketable butter. According to the rule 

 adopted b}^ the Holstein-Friesian Association .80 of a pound 

 of fat is considered equivalent to one pound of butter, while the 

 Association of American Agricultural Colleges and Experiment 

 Stations has adopted .85^ of a pound of fat as equivalent to 

 one pound of butter. If one-fourth of the fat be added to itself 

 in the former case or one- sixth in the latter, the fat may be 

 readily and quickly converted to its equivalent amount of butter, 

 e. g., 18 pounds of fat would be equivalent to 22^ pounds of butter 

 according to the former and 2 1 pounds according to the latter. 

 The average per cent of fat is obtained by dividing the total 

 amount of fat b}^ the total amount of milk produced in the seven 

 days. 



In Table I is given the name and herd book number of the 

 the cow, her owner, age at the time of calving, date of begin- 

 ning the test, number of days from calving to the beginning of 

 the test, pounds of milk for the seven days, average per cent of 

 fat and total pounds of fat for the seven days. The records of 

 the cows are arranged in Tables I and II, (i) according to age, 

 two-year olds coming first, then the three and four year olds, and 

 full aged cows following successively. (All cows five years old 

 or over are considered as of full age.) (2) Under each age, in 

 the order of time in which the cows were tested, beginning with 

 the first test on May 30th, 1894, and continuing in order until 

 the last test on June 25th, 1898. For convenience of reference, 



