Mar. 25, 191S 



Energy Values of Feeding Stuffs for Cattle 



437 



values obtained in a single experiment maj' be regarded as accurate to 

 within the following percentages of the amounts determined: Carbon 

 dioxid, 0.5; water, 6.0; heat, i.o. 



A further test of the accuracy of the work is found in a comparison of 

 the observed heat production with that computed in the ordinary way 

 from the balance of carbon and nitrogen. Comparisons of this sort for 

 57 feeding periods up to the end of 1909 (5, 6) showed an average differ- 

 ence of 0.4 per cent. The results of the later comparisons reduce this 

 difference to 0.3 per cent, or, if the unsatisfactory results of the year 1905 

 be omitted, to 0.04 per cent. The total amounts of heat involved are as 

 follows : 



:6 periods. 68 periods. 



Computed heat production Calories. . i, 338, 887 i, 231, 711 



Observed heat production do. .. . 1,343,071 1,231,251 



Difference do ... . 4, 184 460 



Percentage difference o. 31 o. 04 



While the basis for the computation of the heat production is not alto- 

 gether satisfactory, especially in the absence of determinations of the gain 

 or loss of glycogen by the animal, nevertheless the general agreement is 

 such as apparently to preclude the existence of gross errors. 



FEEDING STITFFS 



The dry matter of the several feeding stuffs used had the following 

 average composition, as shown in each case by concordant analyses of 

 two or more separate samples taken at the beginning of each experiment 

 (Table I). The more important determinations were also repeated upon 

 samples taken when the feed was weighed out for each period, and these 

 period results form the basis of the computations on subsequent pages. 



Table I. — Composition 0/ the dry matter of the feeding stuffs 



Feeding stuff and experi- 

 ment No. 



Timothy hay: 



174 



190 



200 



207 



Red clover hay : 



179 



186 



Mixed hay : 



211 



Alfalfa hay : 



208 



209 



212 



Alfalfa meal : 



212 



Maize stover; 



210, total 



210, portion eaten 



Non- 

 protein. 



Per cent. 



0. 24 



•39 

 ■83 



.24 



1. 61 

 .89 



I. 29 



2.52 

 I. 67 

 2.86 



2.87 



.86 

 .98 



Per cent. 

 38.92 



38.15 



33- 02 

 31- IS 



31.61 

 28.78 



33-78 



31.96 



31- 70 



30. 10 



31. 12 



36.15 

 35-23 



Nitrogen- 

 free 

 extract. 



Per cent. 

 49.01 



49-51 

 51. CI 



54-55 



44.81 

 49-65 



46. 00 



42- 75 

 41.86 

 43-63 



43-17 

 51.46 



Ether 

 extract. 



Per cent. 

 2.08 

 2. 01 

 2. 56 

 2-15 



2. 67 



2-93 



2.30 



1-51 



I. 92 

 I. 96 



1.85 



1.30 

 1. 41 



Heat of 



combus- 

 tion per 

 kilogram. 



Caiories* 

 4-554 

 4,431 

 4,516 



4,505 



4,457 

 4,492 



4,396 



4,403 

 4,330 

 4,368 



4,374 



4,337 

 4,332 



