210 



MANUAL OF FARM ANIMALS 



For a heifer weighing 1000 pounds and yielding 22 pounds 

 of 6 per cent milk : — ■ 



According to this standard, the heifer needs considerably more 

 nutrients than the mature cow, and in the case of high produc- 

 tion calls for more nutrients than the Wolff-Lehman standards 

 provide. This is due to the fact that she needs nutrients in 

 building up her own body as well as for the production of milk. 

 It is worthy of note, however, that in all these cases the Wolff- 

 Lehman ratio is much more narrow than the Haecker ratio. 



Feeding-standards merely guides. — From the foregoing discus- 

 sion of the food requirement for milk it must be apparent that 

 while one should use a standard, it should be considered only as 

 a guide and be modified to meet the conditions, such as the indi^ 

 viduality of the animal and the prices of foods. It is not prac- 

 ticable to attempt to follow standards with strict mathematical 

 accuracy, any more than to follow them slavishly with fer- 

 tilizers or with quantities of seed per acre. 



EFFECT OF FOOD ON COMPOSITION OF MILK 



Of all the problems connected with the feeding of dairy cattle, 

 perhaps none has received more attention than the effect of food 

 upon the composition and quality of the milk. There is a pre- 

 ■s^iling opinion among practical dairymen that one can improve 

 the composition of the milk, particularly with respect to the per- 

 centage of fat, by liberal feeding. This, however, is one of the 



