The Relation of Food tu IMilk-Fat. 49 



the cow is well nourislied, then tlie dairviuau is warranted in feed- 

 ing those cheaper foods which contain less protein and more carbo- 

 hydrates and fat. 



A conclusive answer to the question asked at the beginning is not 

 attempted in this bulletin. The record is given of two long experi- 

 ments with rations having different nutritive ratios, and also a less 

 extended one with a ration containing varying quantities of palm nut 

 meal. Considerable space is given to a summary of the leading 

 experiments relating to the iniluence of food on milk production 

 with especial reference to the quality of tlie milk by which is meant 

 here its percentage of fat. 



The records of these experiments are gleaned from all reliable 

 sources both domestic and foreign. The object is to place before 

 the general farmer and reader a knowledge of what has been done to 

 solve the mooted question uf '' feeding fat into milk " by experi- 

 menters abroad as well as at home. In collecting this data free use 

 has been made of all experimental literature obtainable and reference 

 is usually made to the original article. The Experiment Station 

 Kecord has been used freely, especially for translations of foreign 

 experiments which are reported in periodicals not found in our own 

 library. The attempt has been to make tliis summary as brief as 

 possible and yet give a fair idea of the plan and scope of the experi- 

 ment, together with the results or conclusions obtained. 



Summary of Experiments Concerning the Relation of Food 

 TO THE Percentage of Fat in Milk. 



Jordan"^ experimented on live cows with three different kinds of 

 rations during three periods, the rations being made up so as to con- 

 tain varying amounts of vegetable fats, and found that the yield of 

 milk diminished somewhat in passing from the ration rich in fat to 

 the one containing less fat, and increased slightly after changing 

 again to the fat rich ration. '' The composition of the milk varied 

 but little and no more, or even less, during the three periods than is 

 often observed when the ration is not changed." 



In a later experiment f Jordan fed three cows during three periods 



* Maine Station Annual Report, 1891, p. 62. 

 f Same, 1893, p. 78, 



