Effect of Feed on Yield. 133 



If animals are allowed to starve, the change in the quality of the 

 milk will result only after the reserve deposits of the body have 

 been utilized to their fullest extent, or completely exhausted. In the 

 state of starvation the milk fat shows an approach in its composi- 

 tion to that of the body fat. 



If experiments are started with starving animals, or with 

 animals which only receive small rations, the milk yield, according 

 to Kellner, increases with the added increase of feed. Such cows 

 after an increase of rations yielded: 



With an increase of 1.5 kg. bean bran, the increase of milk 

 amounted to 0.92 and 0.53 kg. 



With 3 kg. bean bran, the increase was 2 . 40 and 1 . 01 kg. 



With 1 kg. malt, the increase was 0.84 and 0.3 kg. 



With 2 kg. malt bran, the increase was 1.31 and 0.40 kg. 



The increase in yield however was not parallel with the in- 

 crease of the ration, but the closer the quantity of milk produced 

 approached the maximal production of the individual, the slighter 

 became the increase in yield. In attempts to increase the produc- 

 tion of the cow, the last liter of milk is the most expensive. It re- 

 quires for its production the largest addition of rations. 



In general it may be said that sufficient quantities of digesti- 

 ble proteins are the fundamental requirements for normal milk 

 production, and that although other food substances are present in 

 sufficient quantities the yield of milk diminishes rapidly when the 

 protein content is decreased below the amount necessary for main- 

 taining the body weight. For 1000 kg. of body weight 1.212 kg. of 

 digestible proteins must be figured, together with a sufficient addi- 

 tion of fat and carbohydrates. Fat and carbohydrates and non- 

 protein nitrogenous substances in sufficient quantities act as econo- 

 mizers of proteins. For continuous milk production an excess of 

 about 0.40 to 0.55 to 0.65 kg. of digestible proteins is required 

 for 10 kg. of milk (Schmeck and Kellner). 



Experiments of Morgen and Fingerling proved that while 

 feeding tasteless non-stimulating food consisting of straw, cut 

 straw, starch and oil, the yield of milk may be increased by the ad- 

 dition of substances which by themselves cannot be utilized in the 

 production of milk, and therefore they are considered stimulating 

 substances which principally stimulate the gland to activity. 



Increased Increased 



Addition yield yield 



in milk in fat 



Malt gm. gm. 



Buckhorn seed 10 gm. 0.8 gm. 



Hay distillate and fennel 2.03 gm. 7.9 gm. 



153 gm. 5.6 gm. 



312 gm. 9.8 gm. 



109 gm. 6.7 gm. 



The percentage of fat increased 0.25 to 0.32%. 



