72 EXPERIMENT STATION KECORD. 



Net energy values of feeding stuffs for cattle, H, P. Armsby aud J. A. 

 Feies iU. S. Dept. Agr., Jour. Agr. Research, 3 (1915), No. 6, pp. 435-491, figs. 

 2).— In this paper are reported tlie results of 76 experiments at the Pennsyl- 

 vania Institute of Animal Nutrition in cooperation with this Department, using 

 the respiration calorimeter and 9 steers in which the balance of matter and of 

 energy was determined. These experiments were carried out during the 

 years 1902-1912, inclusive, and those to the end of 1907 have been previously 

 reported in full from other sources (E. S. R., 15, p. 799; 17, p. 579; 19, p. 866; 

 25, p. 872; 28, p. 68; 30, p. 268). 



It is said that the losses of feed energy from the animal are of two classes, 

 (1) losses of unused chemical energy in the feces, urine, and methane; and (2) 

 losses in the form of heat due to the increased metabolism consequent upon 

 the ingestion of feed. As to the first class it was found that " the losses of 

 energy in methane and urine were relatively greater on light than on moderately 

 heavy rations. Neither the losses of energy in the feces nor the total losses 

 showed a distinct relation to the amount of feed consumed. Individual differ- 

 ences between animals had no very material influence on the losses of chemical 

 energy. The losses of energy in methane may be computed approximately from 

 the amount of total carbohydrates digested. The metabolizable energy per 

 kilogram of digested organic matter showed but slight variations within the 

 same class of feeding stuffs." 



As to the second class it was found that "the heat production is notably 

 greater during standing than during lying, and the difference is greater on 

 heavy than on light rations. The increment of heat production during standing 

 is affected by the individuality of the animal and by the kind of feed con- 

 sumed. An approximate partial analysis of the heat production of the animal 

 into its principal factoi's is attempted. The average energy expenditure conse- 

 quent upon the consumption of 1 kg. of dry matter is reported for 11 different 

 feeding stuffs. The expenditure of energy arising from the consumption of 

 the coarse feeds is not on the whole materially greater than in the case of 

 the concentrates. The increased muscular work of the digestive organs ap- 

 pears to be a relatively small factor of the increased heat production. A 

 scrub steer showed a somewhat greater increment of metabolism consequent 

 upon feed consumption than did a pure-bred beef animal." 



A summary of the average net energy values obtained in these experiments 

 for the following feeding stuffs is given as timothy hay, 1,072 calories; red 

 clover hay, 1,039 ; mixed ha5% 934 ; alfalfa hay, 752 ; maize stover, 887 ; maize 

 meal, 1,803; wheat bran, 1,334; grain mixtures, 1,737 and 1,848; and hominy 

 chop, 2,157 calories per kilogram of dry matter. 



A method is outlined for computing net energy values, in the absence of 

 direct determinations, from metabolism experiments or from the data of ordi- 

 nary feeding tables. 



Related experiments of others are reviewed, aud a bibliography of cited 

 literature is appended. 



Feeding experimental animals on grass tree, C. J. Pound (Ann. Rpt. Dept. 

 Agr. and, Stock [Queensland], 1913-14, p. 112). — Two 12-month-old calves were 

 fed chopped grass tree varying in amounts from 3 to 6 lbs. per day, mixed 

 with a small quantity of bran, without deleterious effects. The calves gained 

 in weight. 



Origin of the Aberdeen-Angus and its development in Great Britain and 

 America {Chicago: American Aberdeen-Angus Breeders' Assoc. 1914, PP- 36). — 

 A history of this breed of cattle, together with notes on the principal families. 

 A bibliography of literature on the breed is included. 



