Date of this Version
Davis, H.P. and Hathaway, I.L. (1931) The vitamin A content of the milk of Holstein, Ayrshire, Jersey, and Guernsey cows (Research Bulletin: Bulletin of the Agricultural Experiment Station of Nebraska No. 54)
A comparative study of the vitamin A content of milk produced by Holstein, Ayrshire, Jersey, and Guernsey cows was made by comparing the growth produced by 560 rats receiving milk from these breeds as their only source of vitamin A. The results showed some slight irregular differences in the gains produced by the milk from the different breeds. When these differences were considered in view of the individual variation of the experimental animals, they appeared negligible. This conclusion was substantiated by a statistical examination of the data. From the results of this study in which the experiments were duplicated, it was evident that under the conditions of these experiments, the difference in the vitamin A content of milk from Holstein, Ayrshire, Jersey, or Guernsey breeds is insignificant.