481 



With reference to the amoimt of skim milk that shonhl be left with the 

 cream in skimming- Cooley cans, trials were made in which the skim milk 

 was drawn off" to within 2 inches, 1 inch, and ^ inch of the cream hue, sam- 

 ples of the skim milk beiii.i;- taken for analysis in each case. Calculated to 

 100 pounds of milk set, the losses of fat in the skim milk were as follows : 



Pounds. 



Skimmed, to within 2 inches of cream line 0. 213 



Skimmed to within 1 inch of cream line 0. 238 



Skimmed to within | inch of cream line 0. 338 



Assuming- the amount of buttermilk to be equal to the difference 

 between the total amount of cream obtained and the fat contained in the 

 cream, and that the buttermilk contained 0.3 per cent of fat, a calcula- 

 tion is made of the total amount of fat lost per 100 jjounds of milk in 

 the skim milk and buttermilk together. 



" This indicates that the loss is practically the same whether 1 or 2 

 inches of skim milk are left with the cream. There is, however, a very 

 material increase in the loss when another half inch of skim milk is 

 drawn off'." 



Injiuence of character of milk upon efficiency of creaming (pj). C-1 1). — 

 The cows of the station herd were divided into five grou^is of froui four 

 to six each on the basis of the fat content of their milk. " The cows 

 in all of these lots were treated alike, receiving the same food and 

 care." The milk from alternate milkings of each lot was creamed by 

 setting in Cooley cans, and that of the other milkings by the Baby 

 Separator ]^o. 2. 



[Wliere the Cooley cans were used] the milk was set in ice water as soon as 

 [jossible after milking, and skimmed after standing from 15 to 24 hours, all of the 

 lots at the same milking being treated as nearly alike as possible. They were 

 skimmed to within 2 inches of the cream line. * * * 



[Where the separator was used] the milk was in some cases separated iniiuediately 

 after milking, while it was still warm ; in other cases it was allowed to stand 2 

 or 3 hours before skimming. Whenever the milk had cooled below 80° F. it was 

 warmed to between 80^^ and 90'-' before separation. 



Ten trials were made with the milk from each lot by the Cooley sys- 

 tem and seven by the separator. Fat determinations were made in 

 the skim milk from every trial. The maximum, minimum, and average 

 of these rcvsults are tabulated. The calculated loss of fat in the skim 

 milk per 100 x)»unds of milk set is given as follows : 



Loss of fat in skim milk 2)er 100 pounds of milk set. 



15155— >"o. 7 1 



