308 THE CHEMICAL COMPOSITION OF MILK. 



TABLE LXVII. 



Heaton has also given a remarkable analysis of a partial 

 milking ; it contained only 0-26 per cent, of fat. 



It is sometimes noticed that a cow, through restlessness or 

 nervousness, holds back her milk, especially if the surroundings 

 be strange. Thus, Dyer has recorded an analysis of milk obtained 

 from a cow at an agricultural show which contained 1 -85 per cent, 

 of fat ; the next day the milk was normal, containing 3-64 per 

 cent, of fat. Many, if not all, of the very low fats recorded in 

 Table LVIII. on p. 301 are due to this cause. 



Influence of Feeding and other Conditions on the 

 Composition of Milk. If the food given to the cattle be suffi- 

 cient both in quantity and ratio of constituents no appreciable 

 variation in the composition of the milk is found on changing 

 the food. The author has noticed that, if the food given makes 

 the cows scour, the milk is likely to be low in fat, and the per- 

 centage of fat is raised by the addition of a more binding food 

 e.g., cotton cake to their ration. 



The figures in Table LXVIII. afford a striking illustration of the 

 effect of food causing scouring on the composition of milk, and 

 show how easy is the remedy. 



A herd of 26 cows (Ayrshires) was turned out into a field of 

 new grass at the end of April, and received no other food ; the 

 percentage of fat fell rapidly, and on May 7 the author saw 

 all the cows milked, and the analyses of the milk given on 

 opposite page were made. 



The cows were very thin, though pronounced by a leading 

 veterinary surgeon otherwise quite healthy, and suffered from 

 profuse diarrhoea, the motions being quite liquid, and containing 

 much undigested food. On this day the food was changed, and 

 the quality of the milk rose steadily till within a week the per- 

 centage of fat was over 3-0 per cent., and remained above this 

 figure. The only cow of the herd which had not been turned 

 out to the new gra^s was No. 13, and it is seen that her milk was 

 practically up to the standard in fat. 



A too highly saccharine diet is not advisable, and may cause 

 a disturbance in the composition of the milk. The author has 

 examined the milk of three cows which had been fed on a ration 



