CALCIUM AND PHOSPHORUS IN THE FEED OF DAIRY COWS. 21 



Cow 54. — This cow aborted during the phosphate feeding 28 days 

 before term. Judging from the history of such cases in the general 

 herd, her milk yield should have been about 10 per cent less than 

 after the control feeding. We have no way of accounting for the 

 actual increase except as the result of the phosphate feeding. 



Cows 63, 71, and 81. — The remaining three animals of Table 1 

 were fed on the control rations before their first calves were born 

 and on the experimental rations before their second calves were 

 born. It is well known that heifers are likely to give more milk 

 with their second than with their first calves; the average increase 

 has been worked out by Pearl and Patterson (14) for Jerseys, and 

 the department has figures obtained from the cow-testing associa- 

 tions for Guernseys and Holsteins. In Table 8 we have given the 

 actual and expected increases ; in calculating the expected differences 

 we have in each case used the set of figures which would give the 

 largest differences, in order to avoid any possible suspicion of favor- 

 ing the results of the phosphate feeding. The milk yield of all 

 three heifers increased after the phosphate feeding decidedly more 

 than would be expected as the result of age alone. We have no 

 way of accounting for the additional increases except as the result 

 of the phosphate feeding. 



Table 2. — Animals from the general herd used only either as experiment or 



control animals. 



CONTROLS. 



No. of animal. 



Date of birth. 



Breed. 



Date of 

 calving. 



Days dry. 



Milk 

 yield. 1 



Fat 

 yield. 1 



59 



Aug. 10,1915 

 Oct. 18,1915 

 Sept. 26, 1915 



Grade Holstein 



do. 



Dec. 26,1917 

 Feb. 6,1919 

 Feb. 6, 1918 



Days. 

 First calf. 

 62 



Pounds. 



568 



1,108 



742 



Pounds. 

 20.5 



64 



40.1 



213 



26.7 











EXPERIMEN 



T ANIMALS. 













21 



1907 



Grade Jersey 



Grade Holstein 



Grade Guernsey... 



Nov. 30, 1918 

 April 20, 1918 

 Jan. 27,1919 

 May 27,1918 



85 



1,458 

 753 

 588 



1,554 



60.9 



67 



Dec. 29,1915 

 April 22, 1916 

 Mar. 18,1916 



First calf 



do 



do 



26.3 



70 



28.3 



214 



46.8 









1 The figures given in these columns represent the number of pounds of milk or fat given from thelOthto 

 the 40th day after calving. 



The animals whose histories are tabulated in Table 2 were used 

 in early experiments in which we were still feeling around for the 

 conditions under which the effects of the phosphate feeding would 

 stand out most sharply and in which the treatment of the subjects 

 was not so carefully controlled as in the later experiments. The 

 results, however, are in general accord with those of the later experi- 

 ments, and it has seemed to us worth while to report them. 



