ANIMAL PRODUCTION. 769 



The volume as a wlK»le constitutes a useful suniuiary of available data on 

 the feeding, care, and management of farm animals and is designed by the 

 author as the first vohmie of a proposed series. It has been the author's aim 

 " to prepare a work adapted to the needs of the student and stockman that 

 would succinctly and fully cover the subject of feeding and foods in a general 

 way, by dwelling, first, on the leading principles or laws that govern feeding; 

 second, on type in the animals to be fed and the balancing of foods for them; 

 third, on the foods "used in feeding; and fourth, on the more important con- 

 siderations that apply to successful feeding. It has also been the constant 

 aim to observe that sequence in treatment that would be natural, orderly, and 

 complete; to discuss the subject with a comprehensiveness that would cover 

 conditions in all parts of the United States and Canada and in a manner so 

 simple that any reader may readily understand what is read." 



Feed as a source of energy, H. P. Armsby {Peiiiisylvaiiia tita. Bui. S.'i, pp. 

 16), — On the basis of experiments with the respiration calorimeter on the com- 

 parative value of different feeding stuffs for steers (E. S. R., 17, p. 3S0), the 

 author discusses the uses of energy, the fuel value of feed, maintenance re- 

 quirements, and related questions, the bulletin constituting a popular summary 

 of some of the more important points brought out in the experimental work. 

 According to his summary, the animal uses the energy which it derives from 

 its feed essentially for 3 purposes, namely, maintenance, external work, and 

 the production of human food. 



" Even when the animal is apparently at rest, many parts of the bodily 

 machinery are still active, and to maintain this activity requires a supply of 

 energy in the feed. If this is withheld, the animal uses instead energy from the 

 substance of its own body and sooner or later perishes. 



'• AVhen the demands for maintenance are met, the energy of additional food 

 may be used by the animal to do external work of various sorts, such as pulling 

 or carrying a load, driving a tread power, etc. 



'• If the animal's feed contains more energy than it needs for its own purposes, 

 it has the capacity of storing up more or less of this surplus energy in the 

 form of meat or fat or milk, and these man uses as food^i. e., as a source of 

 energy for his own body." 



Colorado fodders, W. P. IIeadden (Colorado Sta. Bui. 12'/, pp. 10')). — In con- 

 tinuation of previous work (E. S. R., ItJ, p. 1108) the composition and relative 

 feeding value of alfalfa hay, timothy hay, native mixed hay, saltbush (Alri- 

 plex argcntca), corn fodder, and sorghum fodder were studied. The usual 

 proximate analyses were made, and, in addition, special studies of composition 

 in which the fodders were successively extracted with boiling 80 per cent alco- 

 hol, cold water, boiling water, and, after cooling with malt extract, boiling 1 per 

 cent hydrochloric acid solution, boiling 1 per cent sodium hydroxid solution, 

 and lastly with chloriu, the material remaining being washed with 1 per cent 

 sodium hydroxid and sulphurous acid solutions and the residue dried and 

 weighed as cellulose. Digestion experiments with sheep as subjects were also 

 made with each feeding stuff and the feces were treated with the same reagents 

 as the feeds and the digestibility computed on this basis. The urine was not 

 collected. 



In tests with alfalfa hay, corn fodder, and saltbush, the heats of combustion 

 of different constituents of foods and feces were determined and in most cases 

 estimations were made of the distribution in the various extracts of sugars, 

 f)entosans, methoxyl group, and the amid and proteid nitrogen, together with 

 their respective coefficients. 



