INFLUENCE OP THE PLANE OF NUTRITION UPON MILK 63 



These results are corroborated by a large number of data from 

 other experimental animals which will not be given here. 



Other evidence on this- point is found in the reports of 

 official tests of dairy cattle as reported by the various breed 

 associations. All interested in the practical phases of dairy 

 husbandry are familiar with the immediate application which 

 followed the publication of the facts 4 regarding the possibility 

 of increasing the richness of the milk by these means and the 

 astonishing results that have been obtained in seven day tests 

 of dairy cows in recent years as a result. It is well known 

 that the great increase in butterfat yield in these tests is due 

 largely to a decidedly higher fat percentage. For example 

 i;i 1903 the cow, Sadie Vale Concordia, held the Holstein 

 butter fat record for seven da} T s with a yield of 694.3 Ibs. of 

 milk containing 3.52 per cent of fat. 5 The record up to 1917 

 is 730 Ibs. milk containing 5.54 per cent of fat. 6 At the 

 same time there is no evidence of any appreciable raise in 

 the average fat percentage for the breed. The average fat 

 percentage reported by the Holstein Association for the 

 highest twenty-five cows in seven day tests is 5.1. The aver- 

 age for the highest twenty-five yearly records is 3.96. 



The practical use of this means of greatly increasing the 

 butterfat production temporarily has resulted in an entirely 

 new basis of fixing value for breeding stock among certain 

 of the dairy breeds. 



The question may be raised whether it is not normal re- 

 gardless of the state of flesh of the animal for the fat per- 

 centage to be high during the first four weeks after parturition 

 followed by a decline to a lower level. Data are also at hand 

 showing this is not the case. In Table II are found data giving 

 the fat content by weeks in the milk of cows that were in a 

 moderate state of flesh at parturition. It will be noted that 

 there is a constant rise in the fat percentage from the be- 

 ginning and that the average for the year is decidedly higher 



4 C. H. Eckles, A New Factor Influencing the Per Cent of Fat in Cotes' 

 Milk in Hoard's Dairyman, 40, 23, p. 696, Aug., 1909. 



5 Holstein Friesian Yearbook, 3, p. 93, 1903. 



6 Hoard's Dairyman, 43, 1, p. 14, Jan., 1917. 



