8o Bulletin 152 



or 33 per cent more of milk amd 6.32 pounds or 54 per cent more 

 of fat than No. 169. Number 168 required 23 pounds less of dry- 

 matter for 100 pounds of milk and 10.5 pounds less of dry mat- 

 ter for I pound of fat. 



Under B are arranged the records of eight cows selected from the 

 various ages, each of whom consumed in the neighborhood of 285 

 pounds of dry matter. In production the}^ vary from 236 to 520 

 pounds of milk and from 6.78 to 15.9 pounds of fat, or a 

 variation of 120 per cent in milk and of 134 per cent in fat. In 

 the amount of dry matter required for 100 pounds of milk they 

 vary from 55 to 122 pounds or 122 per cent, and for i pound of 

 fat from 17.35 to 42.5 pounds or 145 per cent. 



Under C is collected some data showing the varying amounts 

 of food required to produce similar amounts of butter-fat in 

 diflferent animals. For the production of about 8.5 pounds of 

 butter-fat in two-\^ear olds, the dr}' matter varies from 226 to 332 

 pounds, a difference of 46 per cent. To produce a little over 11 

 pounds of fat is required a quantity- of dry matter varying from 

 204 to 341 pounds, a difference of 67 per cent. For a similar 

 amount of fat among three-j^ear olds, the consumption of dry 

 matter varies from 285 to 394 pounds, a difference of 38 per cent. 



Among full aged cows the amount of dry matter required to 

 produce about 15.5 pounds of fat varies from 260 to 394 pounds, 

 a difference of 51 per cent. To produce a little more than 20 

 pounds of fat, the variation is still greater, being the difference 

 between 250 and 433 pounds or 73 per cent. 



Under D are arranged the records of the cows w^hich gave the 

 most milk for their age of those that were stall fed. Among two- 

 year olds a difference of a little less than 20 pounds of milk is accom- 

 panied with a difference of over 52 pounds of dry matter, the 

 heifer consuming the most food giving the most milk. This order 

 is reversed among three-\^ear olds where a difference in milk 

 yield of a little more than 105 pounds, is accompanied with a 

 difference of over 138 pounds or 48 per cent of drj^ matter con- 

 sumed, but the heifer consuming the larger amount of food gave 

 the less milk Adeld. The variation among four-year olds in milk 

 5deld is 27^ pounds and in dry matter consumed a little over 78 

 pounds, or 34 per cent, and the cow giving more milk also con- 



