The Dairy Cow — Scientific Findings. 403 



614. Ratio of milk yield to body weight. — Kraemer* states that 

 cows yield during the year from four to eight times their body 

 weight in milk, and that each pound of dry matter fed will return 

 from four- to eight-tenths of a pound of milk, these returns being 

 gauged by the character of the cow, as follows: 



Character Yield of milk Milk per pound dry 



. of cow. in body weight matter in feed. 



Poor 4 times, .4 pounds. 



Medium 5 times. .5 pounds. 



Good 6 times. .6 pounds. 



Very good 7 tunes. .7 pounds. 



Excellent 8 times. .8 pounds. 



615. Percentage fat in successive portions of milk. — At the New 



York (Geneva) Station, 2 Collier examined the milk from 5 cows 

 as drawn, pint by pint, and found the fat in the successive lots as 

 follows: .85, 1.43, 1.68, 2.02, 2.23, 2.65, 3.27, 3.74, 4.05, 4.86, 

 4.48, 4.30, 5.23, while the average of the whole milk was 3.21. 

 The average per cent, of fat in the first and last pints was .85 and 

 5.23, an increase of about 500 per cent The average per cent, 

 of fat in the first and last halves of the milk was 1.92 and 4.35, an 

 increase of 127 per cent. 



The above shows the poverty in fat of the first milk drawn 

 from the cow and the richness of that last drawn. It shows that 

 those who allow calves to have the first milk from the cow and 

 reserve the strippings withhold the richest milk. 



616. Concerning fat globules. — Collier^ places the average se- 

 cretion of milk by the cow at . 7 of a pound or 19. 6 cubic inches 

 per hour. One ten-thousandth of a cubic millimeter of milk was 

 found to contain on an average 152 fat globules. (828) From 



? these data he concludes that the average cow in the Greneva Station 

 herd secreted 138,210,000 fat globules each second. According 

 to Babcock* the number of fat globules in a quart of milk of 

 average composition is not less than 2,000,000,000,000. These 

 figures are beyond comprehension, and should increase our in- 

 terest in the marvelous processes of animal life. Appreciating 



* Die Schule der Schweizer-kasers. 

 « Rept. 1891. 



«Rept. New York (Geneva) Sta., 1892. 



* Bui. 18, Wis. Expt. iSta. 



