26 



BULLETIN 945, U. S. DEPARTMENT OF AGRICULTURE. 



GRAIN MIXTURE E. 



Corn-and-cob meal 55 pounds. 



"Wheat bran 30 pounds. 



Linseed meal 15 pounds. 



NaCl 1 pound. 



GRAIN MIXTURE F. 



Ground oats 28 pounds. 



Linseed meal 20 pounds. 



Cottonseed meal 10 pounds. 



Gluten feed 14 pounds. 



Hominy feed 14 pounds. 



Wheat bran 14 pounds. 



NaCl 1 pound. 



ACCOUNT OF UNSUCCESSFUL AND INCOMPLETE EXPERIMENTS. 



Many experiments on the effects of phosphate feeding were begun 

 and then had to be abandoned because the animals aborted or failed 

 to calve, or for other reasons. In other cases phosphate was fed to cer- 

 tain animals, but under rather different circumstances from those in 

 the experiments which have been reported. We wish to mention 

 briefly these unsuccessful and incomplete experiments partly because 

 the results sometimes furnished interesting hints, partly in order to 

 avoid any suspicion that the results reported for the successful experi- 

 ments might be cases unconsciously selected in which the milk yield 

 happened to be large after the phosphate feeding. 



Several animals were started on the control rations, and subse- 

 quently either aborted or turned out to be sterile. It is not necessary 

 to say anything about these further than that, in the cases where they 

 aborted, the milk yields were such as would be expected from a con- 

 sideration of their histories in comparison with those of the rest of 

 the general herd. 



Cow 63, whose 1918 and 1919 lactation periods have already been 

 described in detail, was started again on the basal rations in 1920. 

 She carried her calf to term, but acquired an acute general infection 

 after she had been milking about two weeks, which rapidly reduced 

 her milk yield to a very low point, and finally made it necessary to 

 have her slaughtered. She began this lactation period, however, with 

 a milk yield which promised to be as good as or better than that of 

 1919 after the phosphate period. It is to be remembered that her dry 

 period in 1919 on the phosphate feeding was 103 days ; and her dry 

 period in 1920 was also about 100 days. We are inclined to think that 

 these long dry periods made it possible for her to store up a good 

 quantity of calcium and phosphorus, and it would not be surprising if 

 the effect of the long dry period with phosphate feeding in 1919 lasted 

 into 1920. 



Several cows started on the phosphate feeding turned out to be 

 sterile ; and one aborted in addition to cows 49 and 54, whose histories 

 have already been reported in detail. The abortion in question oc- 

 curred at a period when it was the custom to remove aborting cows 

 from the farm immediately, and before we realized that cows which 



