FACTORS THAT AFFECT COMPOSITION OF MILK 63 



its relation to the percentage of fat in the milk. The results of 

 his work indicate " that when the cow has a considerable amount 

 of fat stored upon the body at the beginning of the milk period the 

 milk will contain a higher fat percentage for a certain period 

 than will be the case if the same animal is thin in flesh at the 

 beginning of the milking period. 



" On the following page are the records from a series of ani- 

 mals, all of which were in good condition and some of them 

 excessively fat at calving time. The records in some cases 

 are not quite complete, which is indicated by the absence of 

 some figures. The first six animals represent the Holstein 

 breed and the last two the Ayrshire. 



" It will be noticed by studying these that in each case the 

 percentage of fat starts in high and gradually comes down. The 

 records for the remainder of the lactation period are given in the 

 lower part of the table by months. By comparing the percent- 

 age of fat in the milk for the first twenty days with these records 

 for the remainder of the lactation period it will be observed that 

 the fat-content during the first twenty days was abnormally high. 



" One of the necessary conditions to bring about this abnormal 

 percentage of fat in the beginning of the lactation period seems 

 to be under-feeding. This is illustrated by the table [page 65]. 

 As is well known to all practical herdsmen, it is impossible to 

 feed a cow that is in good flesh and is at the^same time an animal 

 with strong dairy characteristics a sufficient amount of feed 

 during the first month after calving to maintain the weight of 

 the animal. There is certain to be some decline in weight ; and 

 for this reason where a cow is more moderately fat at the be- 

 ginning of the lactation period there is almost certain to be 

 some effect on the richness of milk for a time regardless of 

 whether any special attempt is made to bring this about or not. 



" The table is the record of an experiment with a Jersey cow. 

 This animal was fed liberally when dry in order that she might 

 be decidedly fat at parturition. Following the birth of the calf 



