A STUDY OF RATIONS FED TO MILCH COWS. 



103 



III the second test the ration zvas varied according to the yields 

 of butter fat produced in the first test. Two grain mixtiwes were 

 used in this test; the first was included with the coarse fodders in 

 zvhat was called a basal ratio7i, which was planned to contain 

 about the same amount of protein as the average 7'ation used in 

 the first test; the second grain mixture, called a protein mix- 

 ture, was chiefiy m,ade tip of co7icentrated nitrogenous grai?i feeds , 

 conibijied in such proportions as to fur7iish, in the different cases, 

 between .2 and .j of a potind of protein for each pound of the 

 mixture. The plan of feeding in this test was to use the basal 

 ration u7iiformly for all cows 171 the test, and to add to this certai7i 

 qna7itities of the protei7i mixture, varyi7ig for the differeiit cows 

 acco}'di7ig to the average daily amou7tt of butter fat they had pro- 

 duced ifi the first test. 



The res7ilts of the two tests with each of the four he7'ds are sunt- 

 marized in the following table; the figures i7i the table a7'e aver- 

 ages for the total 7iuviber of coivs ifi each test. 



Table 56. 

 Summary of daily ratio7is fed, a7id daily 77iilk a7id butter yield. 



T, 



'. { 



V, 

 W, 



1st test, ( 

 2d test, i 



1st test, \ 

 2d test, \ 



1st test, 

 2d test, 



1st test, 

 2d test, 



Daily Ration per Head 



oj o 



5^ 



Lbs. 



[-75 

 [.90 



[.77 

 J. 44 



2.19 

 2-34 



2.40 

 2.74 



Be. a 



f* Oy ^ 



Cal. 



27960 

 24860 



29480 

 29610 



35140 

 30320 



30990 

 29710 



'Z 1 "J 



7.6 

 6.0 



8.0 

 5.5 

 7.6 



Cts. 



17.0 

 17. 1 



18.6 

 19.9 



21.7 



6.0JI9.6 



5.920.1 



4.8 20.0 



10.3 



10. 1 



II. 8 

 II. 5 

 13.0 



Average 

 Daily 



Lbs. 



14. 1 

 14.7 



17.4 

 18.0 



19.4 

 11.4I19.I 



II. 8 

 II . I 



19.6 

 1.8. 1 



Lbs. 



87 

 94 



98 

 10 



04 

 06 



Cost of Food 

 TO Produce 



100 lbs. I lb. 

 Milk. Butter. 



1. 16 



1.03 



1.03 

 1. 10 



19.512 

 18.2 II 



19.0 12 



18. 1 10 



20.9 13 

 18.5 II 



19.5 II 

 20.0 II 



The cost of the average ratio7i was less i7i the second test for 07ie 

 he7'-d, p7-actically the sai7ie for two he7'ds, aiid was }no7-e i7i the 

 second test for one herd. The ave7'age food cost of produciiig 100 



* Total cost less value of obtainable manure. 



+ On the assumption that the amount of butter that can be made is equivalent to 

 seven-sixths of the amount of butter fat produced. 



