MILK TESTS BY DR MACADAM 311 



are produced at the highest temperatures. The reduction in 

 value of the cow may now (1906) be estimated at 8 between 

 the " laid in " and selling price, a sum far too large to be 

 balanced by the value of the manure. 



The decidedly unnatural method of treatment which 

 involves the imprisonment of the cows in comfortable 

 quarters, but deprived of exercise, has led to much dis- 

 cussion as to its influence on the quality of the milk 

 produced. 



In the spring of 1900 the late Dr Stevenson Macadam 

 threw much light on the question, by a careful and elaborate 

 series of tests for the Edinburgh and Leith Dairyman's 

 Association, of average samples of the milk of 123 cows 

 from a total of 681 cows housed in sixteen dairy byres 

 belonging to the great system of milk production in the 

 Scottish Metropolitan centre. The mixed milk samples 

 ranged in composition in 100 parts by weight as follows : 



MORNING MILKINGS. 

 Total solids, from 12-51 to 11-19 

 Fat of solids, 372 to 2-16 

 Solids not fat, 9-45 to 879 

 Ash in solids, -84 to 71 



FORENOON MILKINGS. 



From 14-08 to 12-53 



4-96 to 3-49 



976 to 8-64 



85 to 71 



Several tests with smaller numbers of cows indicated that the 

 afternoon or third milking in the day, although much richer 

 than the early morning's milk, was not quite up to the product 

 of the forenoon milking. 



The tests have not produced any evidence to break down 

 the rule that the quality of milk can only be immediately 

 affected to the extent of a small fraction of a percentage of 

 cream by the character of the food given. If the sloppy 

 forcing food has any important influence upon the quality of 

 the milk, it must be through its influence in the first instance 

 on the constitution of the animal. The striking difference 

 between the proportions of solids in the morning's milk when 

 contrasted with those of the two later milkings, is to be 

 accounted for by the great length of time which elapses 

 before the morning milking. 



Wolffs Feeding Standard for milch cows of 1000 Ibs. 

 live-weight was fixed some years before the end of last 

 century at 24 Ibs. of dry matter, containing 2-5 Ibs. of protein, 

 1 2*5 Ibs. of carbohydrates, and about 4 per cent, of fat ; yield- 



