Studies in Mii.k Secretion. 79 



• 



digest the larger product she is apt to give. The fame the cow 

 brings to the herd and the prize she wins, and not the milk and 

 butter, are to pay for the food. It is a question whether the 

 " Economic Food Test," where the attempt is to feed as little 

 and produce as much as possible, is a step in the right direction. 

 Would it not be a better principle to, in some way, bring out 

 those animals which can make the most economic use of large 

 amounts of food ? 



Under the head of " Summary of Table II " we have gathered 

 such data as will show the great variation in production from the 

 same or similar amounts of food when given to different animals. 

 As a matter of convenience, when referring to the figures in the 

 summary we shall omit fractions as much as possible and speak 

 in round numbers. 



Under A are arranged two animals from each of the various 

 ages which consumed the same amounts of the same kinds of 

 food, together with their production of milk and fat. Each two 

 animals were in the same herd and were tested at the same time. 

 Of the two-year olds, numbers 20 and 23 each consumed 282.87 

 pounds of dry matter, but in production No. 20 exceeds No. 23 

 by about 1 1 1 pounds of milk, or 45 per cent, and over 2.5 pounds 

 of fat, or 33 per cent. Number 20 also required 36.5 pounds 

 less of dry matter for 100 pounds of milk and nearly 9 pounds 

 less of dry matter for i pound of fat than No. 23. Of the three- 

 3^ear olds numbers 95 and 99 each consumed 204.82 pounds of 

 dry matter. The difference in production is about 130 pounds 

 of milk or 57 per cent, and 5.3 pounds of fat or 69 per cent in 

 favor of No. 99. The latter required about 32 pounds ICvSS of 

 dry matter for 100 pounds of milk and 11 pounds less of dry 

 matter for i pound of fat than No. 95. 



Among the four-year olds numbers 138 and 140 each consumed 

 247.24 pounds of dry matter. From this No. 138 produced 95 

 pounds or 31 per cent more of milk and 1.367 pounds or 13 per 

 cent more of fat than No. 140. Number 138 also required 19.6 

 pounds less of dry matter for 100 pounds of milk and 2.7 pounds 

 less of dry matter for i pound of fat than No. 140. 



Of the full aged cows numbers 168 and 169 each consumed 

 345.73 pounds of dry matter, but No. 168 produced 132 pounds 



