14 BULLETIN 945, U. S. DEPARTMENT OF AGRICULTURE. 



fcained in her rations during the years 1914, 1915, 1916, and 1917 

 were calculated and compared with the quantities required for her 

 maintenance and for her milk and fat yield according to the Savage 

 standard, and it was found that she received, on the average, a sur- 

 plus of about 8 per cent protein and about 9 per cent total nutri- 

 ment. She was on pasture for 46 days during the four years under 

 consideration. She calved normally in the autumn of each year. 

 Her dry periods were 50 days on the average. 



In 1914 she gave 12,182 pounds of milk ; in 1915, 8,269 pounds ; in 

 1916, 7,224 pounds; in 1917, 5,708 pounds; and in 1918, 4,796 pounds: 

 In 1918, she was given a dry period of 78 days, and, during the last 

 40 days of this period, was fed a much more liberal ration than 

 during her previous dry periods. She calved October 30, 1918, and 

 her milk yield for 1919 rose to 8,711 pounds. 



During her dry periods in 1914, 1915, 1916, and 1917 she was fed 

 approximately the same rations as those fed to cow 17 in her corre- 

 sponding dry periods. During the last 40 days of her 1918 dry 

 period she was fed daily 11 pounds of grain mixture C, 11 pounds 

 alfalfa hay, and 26 pounds corn silage. Her milk yields in pounds 

 for the first clear month after calving in each of the five years under 

 consideration were as follows: December, 1914, 1,138 pounds; Octo- 

 ber, 1915, 1,230 pounds; October, 1916, 896 pounds; October, 1917, 

 579 pounds; December, 1918, 1,293 pounds. 



For the same reasons as have been given in the case of cow 17, the 

 greatly increased milk yield after the 1918 calving is to be attributed 

 to the more liberal ration fed in the 1918 dry period. It should be 

 mentioned that this cow was milked three times a day during De- 

 cember, 1918, and only twice in the other months above recorded. 

 But the increase in milk yield to be expected from this change in 

 treatment has been much studied at Beltsville ; it could hardly have 

 been more than 10 per cent in a case such as that under consideration. 

 The actual increase as between October, 1917, and December, 1918, 

 was more than 120 per cent. 



EFFECTS, ON MILK YIELD, OF FEEDING PHOSPHATE WITH ALTERNATED 

 RATIONS DURING DRY PERIOD. 



These experiments may be generally described as follows : Cows were 

 dried off about two months before they were due to calve and were 

 fed, during their dry periods, a basal ration containing 3 to 6 pounds 

 of grain, 4 to 5 pounds of alfalfa hay, and 30 pounds of corn silage. 

 Half of the animals were used as controls and were fed the basal 

 rations without supplement. The others received the same basal 

 rations supplemented with sodium phosphate, the grain and hay of 

 the rations being fed on alternate days. In many cases the same 



