126 Scientific Proceedings, Royal Dublin Society 



other hand, twelve cows aged eight years and nine years, incki- 

 sive, on the average, in their fifth month of lactation, yielded ten 

 four-fifth quarts of milk daily, containing in the morning, 13'39 

 per cent, of solid matter, and in the evening, 13-96 per cent. 

 The richest specimen of milk, save one, was yielded by a cow 

 (No. 35) eight years old, and in the tenth month of lactation ; 

 she only, however, gave six quarts of milk the day on which a 

 specimen of it was taken for analyses. There were only four 

 cows aged four years, and the average composition of their milk, 

 was — 



Per Cent. 



Solids, • 12-245 



Water, 87-755 



100-000 



Their average yield was eleven one- fourth quarts. 



The superiority of the old cows in giving more and better 

 milk, may in part be due to the fact, that it is only good milch 

 cows that are, as a rule, kept in the dairy for several years ; the 

 young cows that give poor milk, are often put into the stall to 

 fatten. 



Influence of Period of Lactation on the Quality of Milk. 



The belief that milk becomes deteriorated in quality towards 

 the end of lactation, is not supported by the results obtained by 

 these experiments, so far as they go. Eleven of the forty- two 

 cows were giving milk from eight to ten months, the average 

 yield of their milk was six four-fifth quarts, which was much 

 below the average yield of all the forty-two cows. The total 

 solid matter in their morning's milk, was 13-57 per cent., and in 

 their evening's milk, 13-96 per cent. 



At an advanced period of lactation milk becomes scanty in 

 quantity, but its quality — at least as shown in the cases of the 

 eleven cows in question — becomes on the whole improved. 



Six cows were giving milk for periods less than one month. 

 They yielded thirteen quarts daily each on the average. The 

 solid matters in their morning's milk, were 12-70 per cent., and 

 in their evening's milk, 13-21 per cent. 



Eleven of the cows were giving milk from one to two months 

 They furnished on the average, eleven and a half quarts per diem. 



