76 Repokt of the Department of Animal Husbandey of the 



upon this subject has led to a number of feeding experiments at 

 this station. 



Aside from the usual increase in cost of food no results have 

 discredited the moderate use of animal food from healthful sources. 

 In general, rations entirely of vegetable origin have proved much 

 less efficient than corresponding rations which contained animal 

 foods. But it appears that the inferiority is due in some instances 

 more to the lack of sufficient mineral matter than to the less 

 efficient forms of »the other food constituents. 



The data from some of the preliminary feeding trials were pub- 

 lished in Bulletin 149. The rations then fed contained equal 

 amounts of protein; but in part of the ration from two-fifths to 

 one-half of the protein was from animal food, while in contrasted 

 rations it Avas derived mostly from vegetable sources, although 

 some came from milk curd. Subsequent experiments have cor- 

 roborated the results then obtained and added to their significance 

 by furnishing supplementary and more extended information. In 

 one series rations in which about 19 per ct. of the dry matter 

 and 37 per ct. of the protein came from animal food proved 

 superior to rations containing an equal amount of protein derived 

 entirely from vegetable food. The rations were similar in nutri- 

 tive ratio but the one in which animal food was used contained 

 more than tAvice as much mineral matter and somewhat more fat. 

 In another series the deficiency of mineral matter in the one ration 

 was made good by the addition of bone ash, so that the propor- 

 tions of protein, ash and fat were alike in the contrasted rations. 

 With this addition a ration of vegetable food was as efficient during 

 ceri:ain periods for chicks and hens as a ration containing animal 

 food. For ducklings the vegetable-food ration was thus improved 

 but still did not approach in efficiency the animal food ration. 



FIRST SERIES OF EXPERIMENTS. 



In this series of experiments ten lots of chicks were fed for ten 

 or twelve weeks and four combined lots afterward for either four 



