24 



BULLETIN 945, U. S. DEPARTMENT OF AGRICULTURE. 



Table 7. — Cows fed alternated rations with phosphate during dry periods oefore 



calving. 





Period 

 during 

 which 

 weigh- 

 ings were 

 taken. 



Average 

 daily 

 gain. 



Average daily ration. 



No. of 

 animal. 



Feed. 



Quantity. 



Feed. 



Quantity. 



Feed. 



Quantity. 



17 



21 



50 



71 



SI 



Days. 

 52 

 80 

 30 

 30 

 31 



Pounds. 

 0.93 

 1.57 

 2.50 

 1.87 

 1.03 



Grain CP... 



Grain CPi-. 

 do 



Grain CP... 

 do 



Pounds. 

 4i 

 6 

 5 

 3 

 3 



Alfalfa hay. . 



do 



do 



do 



do 



Pounds. 

 4 

 5 

 4 

 4 

 3 



Corn silage.. 



do 



do 



do 



do 



Pounds. 

 30 

 30 

 30 

 30 

 30 



It seems worth while to give in more detail the histories of two 

 animals of which the weight changes on the experimental feeding 

 were followed for comparatively long periods. 



Heifer 74 was born October 15, 1916. From October 19, 1918, to 

 January 15, 1919, she was fed alternated rations with phosphate, re- 

 ceiving as a daily average 3 pounds of grain mixture CP 13 4 pounds 

 alfalfa hay, and 30 pounds corn silage. She was farrow during this 

 period. Her weights were as follows : October 24, 1918, 754 pounds ; 

 November 23, 1918, 804 pounds; December 23, 1918, 890 pounds; 

 January 12, 1919, 930 pounds. 



Cow 21 was born in 1907. From August 28 to November 30, 1918, 

 she was fed alternated rations with phosphate, receiving as a daily 

 average 6 pounds of grain mixture CP 15 5 pounds alfalfa hay, and 30 

 pounds corn silage. She had calved November 7, 1917, and became 

 dry September 6, 1918. She calved again November 30, 1918. 

 During the period of phosphate feeding her weights were as follows : 

 September 2, 1,027 pounds; October 2, 1,107 pounds; November 1, 

 1,143 pounds; November 21, 1,153 pounds. 



Her best previous month's record for milk yield on the Belts ville 

 farm was made in October, 1914, and amounted to 1,041 pounds. Af- 

 ter this her milk yield gradually fell off ; the best month's production 

 after the 1917 calving was 469 pounds. She was in very good con- 

 dition when she calved in 1918; in December, 1918, she produced 

 1,276 pounds of milk, and in January, 1919, 1,315 pounds. 



These two cases show clearly that sodium phosphate may be fed 

 to cows for long periods in large amounts without producing any 

 deleterious effects on the digestive and assimilative processes. 



QUANTITATIVE RESULTS. 



In Table 8 and figure 3 an attempt is made to estimate how much 

 the alternated feeding with phosphate increased the milk yield in 

 the cows of the general herd under the conditions of our experiments. 

 The column headed " Expected yield after alternated rations with 



