EXPERIMENT STATION BULLETINS. 259 



hay, and 10 pounds of wheat bran per day make a ration that keeps a 

 thousand pound cow in good condition and allows a full flow of milk. A 

 trial of this ration for a period of reasonable length, say for a whole win- 

 ter, noting the results in the increase of live weight of the cow or in milk 

 and butter yielded, is a valuable experiment. Other dairymen want to 

 profit by the results of this experiment but one of them has silage and no 

 clover hay, and another has clover hay but no silage. How can these 

 cow feeders gain anything from the experience of the first dairyman? 



Beginning in Germany and France a host of experiments were per- 

 formed with dairy cows in full milk. All sorts of fodders and grain 

 feeds were used. A record was kept of the amounts of each consumed, 

 the resulting yields in milk and butter were recorded, the various foods 

 were analyzed and digestion experiments performed with them. From 

 the results of a multitude of such experiments performed partly by prac- 

 tical feeders and partly by the German experiment Stations, Dr. Emil 

 Wolff, the Director of the Hohenhein Experiment Station, after careful 

 study proposed a feeding standard for milk cows per day and thousand 

 pounds live weight. Taking the average of a great number of experi- 

 ments and practical feeding trials he found that the medium sized cows of 

 Germany giving a satisfactory flow of milk, required sufficient food to 

 furnish daily 24 pounds of dry matter; that in this dry matter there was 

 two and one half pounds of digestible protein. He found farther that, 

 with the ordinary feeding stuffs obtaining in Germany, 24 pounds of dry 

 matter containing 2.5 pounds of protein would contain also 12.5 pounds 

 of carbohydrates, and a little less than one half a pound of fat. 



Prof. Wolff farther suggested as an observation justly warranted by 

 the results of the many experiments whose records were before him, that 

 to secure the best results, for every pound of protein in the ration there 

 should be fed about five and four tenths pounds of non-nitrogenous mater- 

 ial. It is believed that one pound of fat is equal in feeding value to two 

 and one quarter pounds of digestible carbohydrates. In estimating the 

 non-nitrogenous materials to compare with the protein, the fat of the 

 ration is multiplied by two and one quarter and added to the digestible 

 carbohydrates. 



It is not necessary here to go into a discussion of the part played by 

 protein in the nutrition of the cow. The transformations which take 

 place in her body are still largely enveloped in mystery. It is a matter 

 of experience, however, that where the cow receives less than two and 

 one-half pounds of protein per day she cannot make her maximum yields. 

 She has no creative ability, she can simply transform the materials of her 

 food into flesh or fat or milk. The composition of the latter is fixed. 

 For every pound of fat she secretes in her milk she must produce, with it, 

 fully a pound of casein, a material practically identical in composition 

 with the protein of her food. Again an uncertain, but not small amount 

 of protein must be used up in the body to carry on the vital functions. 

 The sum of these two demands, for the casein of the milk and for the 

 support of life, it not less than two and one-half pounds for a cow of aver- 

 age size in normal condition and giving a fair flow of milk. These were 

 the conclusions of Prof. Wolff. 



In January 1894, a bulletin entitled "One Hundred American Rations 

 for Dairy Cows", written by Prof. F. W. Woll, was issued by the Wiscon- 



