672 EXPERIMENT STATION EECORD, 



maintenance, that which remained available lor product ranged from 7.23 to 

 10.52 lbs. and averaged 9.11 lbs. Of this there appeared in the milk solids 

 yields ranging from 4.401 to 5.481 lbs. and averaging 4.952 lbs." 



During the four winters in the period previous to 1005 the cows received per 

 1,000 lbs. live weight 16.22 lbs. of nutriment per day, with a nutritive ratio 

 of 1 : 6.2, and returned an average daily product of 4.699 lbs., being 1 lb. of 

 product to 1.77 lbs. of net nutriment. 



During the four succeeding winters the cows received 17.83 lbs. of nutri- 

 ment daily with a nutritive ratio of 1 : 8.1 and returned an average daily prod- 

 uct of 5.205 lbs., being 1 lb. of product to 1.9 lbs. of net nutriment. 



A study of the variation in nutriment consumed per 1,000 lbs. live weight 

 shows that the average consumption ranged from 15.15 to 18.44 lbs. per day, and 

 the average for seven winters was 17.08 lbs. The average product yielded 

 ranged from 4.G93 to 5.481 and averaged 5.031 lbs. of water-free solids. Aside 

 from two winters when conditions were abnormal the jjercentages returned in 

 product during the other years were remarkably uniform, the greatest variation 

 being only 0.9 per cent. The average percentage returned in product for all 

 seven years was 29.49. 



Analyses were made of 544 samples taken from 7,616 milkings, and the milk 

 divided into 10 grades testing from 2.5 to 7 per cent fat. It is seen that " as 

 milk increases in fat content it also increases in protein content, but not at the 

 same rate. In a general way, an increase of 0.5 per cent in fat is followed by 

 an increase of 0.02 per cent in protein. . . . The sugar content of milk increa.ses 

 from 4.6 per cent in milk testing 3 per cent fat to 4.98 per cent in 5 per cent 

 milk, and then gradually decreases to 4.84 per cent in 7 per cent milk. The 

 carbohydrate efpiivalents of the total solids of the different grades of milk 

 range from 14.03 for 3 per cent milk to 24.81 for 7 per cent milk. The nutritive 

 ratio of the various grades of milk ranges from 1 : 4.23 for milk testing 3 per 

 cent fat to 1 : 4.88 for milk testing 7 per cent fat. In 3 per cent milk there are 

 2.43 lbs. of solids-not-fat to 1 lb. of milk fat; and in 6 per cent milk, 1 lb. of 

 fat to 1.45 lbs. not fat, indicating that milk fat only is not a logical basis for 

 feeding for milk production." 



Comparing the relation of the solids of milk taken from cows while on low- 

 protein ration and on niodium-protein ration, it is shown "that without excep- 

 tion the cows gave milk containing a lower percentage of solids when fed a 

 ration containing a nutritive ratio of 1 : 9.4 than they did when receiving 

 rations ranging in nutritive ratio from 1:6 to 1 : S.3 and when on pasture. 

 There was also a depression in both fat and protein in every case. Taking the 

 total solids as a basis the fat is lowered 1.2 per cent and the protein 1.3 per 

 cent, and the milk sugar or carbohydrate raisetl 2.2 and the ash raised 0.3 per 

 cent, thus offsetting the depression in fat and protein." 



During the first four years, when the nutritive ratio of the rations averaged 

 1 : 6.2, " the daily protein supply was 1.95 lbs. with a daily yield of 24.5 lbs. 

 of milk containing 1,045 lbs. of fat and 2.11 lbs. of solids-not-fat, while during 

 the last four years [when the nutritive ratio averaged 1 : 8.1], the daily protein 

 supply was 1.745 lbs. with a daily average yield of 25.6 lbs. of milk containing 

 1.067 lbs. of fat and 2.244 lbs. of solids-not-fat. 



" Of the 1.95 lbs. daily protein supply during the first four years, 0.64 lb. is 

 the protein calculated for maintenance. . . . The daily average protein content 

 in the milk was 0.781 lb., being a return of 1 lb. of milk protein to 1.68 lbs. of 

 net crude protein in the ration, with a yield of 4.462 lbs. of total product in 

 milk solids reduced to a common factor. During the last four years there 

 was a daily supply of 1.74 lbs. of crude protein with calculated protein require- 



