MILK. 



53 



The milk of different animals varies in composition, 

 as will be plain from the following table. 



Of these analyses, 1 and 4 are by Dr. Lyon Playfair ; 3 

 is the average of 2 analyses by Haidlen ; 5 is the average 

 of 5 analyses by Peligot ; and 2, 5, 7, 8, and 9 are by Henry 

 and Chevallier. 



As regards the milk of the cow, it differs in composi- 

 tion, as has been already said, according to the breed, age, 

 and food of the animal. It also varies exceedingly ac- 

 cording to the period since the birth of the calf. Thus, 

 the first- drawn milk produced during the labour and excite- 

 ment of parturition contains an extraordinary quantity of 

 casein, and is otherwise different from ordinary milk ; no 

 doubt naturally beneficially so to the young in the first day 

 or two of its life, during which time the milk not used by it 

 and drawn from the cow is unfit for any other use, and is 

 thrown to the pigs' trough. If this "colostric " condition, 

 as it is termed, of the milk be prolonged, the purgative 

 effect, beneficial at first, which it produces on the calf, 

 becomes injurious. Too generous feeding after parturition, 

 we are informed by Professor Simonds,* tends to the 



* Vol. XIX. of the Journal Eng. Agr. Soc. 



