THE FEEDING OF MILCH CATTLE 339 



that for the production of 10 kg. (22 Ibs.) of milk 

 0-55-0-65 kg. (ij-ij Ibs.) protein and a starch 

 equivalent of 2-0-27 kg. (4|-6 Ibs.) are necessary 

 in addition to the nutrients required for the main- 

 tenance of life (p. 246). In the daily ration 0-5-0-6 

 Ib. of digestible fat may be given per 1000 Ibs. live 

 weight without any unfavourable effect (p. 332). 



The amount of food must naturally be regulated 

 according to the yield of milk, for a cow giving 

 40 Ibs. of milk a day will, of course, require more 

 nutrient than one giving 16 Ibs. If all the cows are 

 fed alike, as is so often done, and the quantity of 

 food arranged for the average yield of the herd, 

 there will be some cows getting too little and others 

 too much food. Both cases act against the pro- 

 duction of milk, for if the animal is starved the 

 mammary gland is weakened and the natural 

 decrease of milk is accelerated, which is injurious 

 to the milking capacity of the calves which follow ; 

 whilst if the mammary gland becomes fat its pro- 

 ductive power is also diminished. Therefore it 

 cannot be too strongly insisted that the feeding 

 should be individual that is, the cows in a herd 

 should be divided into, say, five groups, according 

 to the yield of milk, and food proportionate to 

 the amount of milk should be given. It is not at 

 all necessary to place the animals of the same group 

 near to one another ; all the cows may be given 

 the same basal ration, but the mixture of concen- 



