688 EXPERIMENT STATION RECORD. 



sparing' of protein when the wnpi^ly was short than wlien it was a])un(lant, they also 

 show that sheep can thrive mi bnt Uttle more than half the protein than has })een 

 usually considered advisaljle." 



Making corrections for gain or loss of Hesh, it was computed that on an average 

 the sheep required 2,009.8 calories for maintenance on a basis of 46.4 kg. live weight 

 exclusive of wool, which is equivalent to 2,096 calories per 50 kg. shorn weight. 

 The author assumes that on an average 10.3 gm. of wool is produced per day and on 

 a basis of chemical composition calculates that this amount has an energy value of 

 20.55 calories. 



"As the maintenance ration of a sheep is approximately 2,000 calories per head 

 per day, it will be seen from the above figures how small a draft is made for the 

 growth of the wool. This also helps to explain the fact, that has l)een observed, 

 that when the ration is insufficient for maintenance the growth of wftol is bat 

 sligh tl y reduced . ' ' 



The requirements of sheep in proportion to weight ami surface area are discussed, 

 and the conclusion reached that "in proportion to its boily surface the sheep is more 

 economical of its food than the steer." 



Throughout the test the amount of water consumed was recorded and it was found 

 that the average amount drank per sheep per day on a hay ration was 1.57 kg. On 

 hay and corn, 2 : 1, it was 1.29 kg., and 1.11 kg. on a ration of hay and corn, 1 :2. 



In connection with the above experiments some tests were made to determine the 

 amounts of nitrogen and carbon lost in drying feces, and the chemical bodies in 

 which the loss occurs. On an average the feces from hay alone lost 6.6 per cent of 

 the nitrogen originally present. Those from hay and one-third grain 7 Y)er cent; 

 and from hay and two-tiiirds grain 7.3 per cent. These differences are so slight and 

 the differences between duplicates are so great as to indicate that the amount of loss 

 is not dependent on the kind of feed nor on the individuality of the sheep. The 

 losses are probably dependent on the bulk of the material and the temperature to 

 which it is exposed. 



In one case it was ftnind that 0.571 per cent of the final dry matter was lost as car- 

 bon and 0.390 per cent as nitrogen. According to the author "the common acids 

 2>ro(luced by the action of the ferments of the digestive canal are acet'c and l)utyric 

 acids. In one case the proportions were two parts of acetic to one of butyric acid. 

 In most cases the proportions of Imtyric acid were less. ... It Is probable tliat in 

 air-drying, sheep feces lose 1 per cent of their heat value in the form of ammo- 

 nium acetate in addition to ammonium carbonate and an additional, though small, 

 quantity in skatol and other volatile organic compounds. In estimating the energy 

 value of the rations eaten in the accompanying digestion experiments no allowance 

 has been made for this heat value lost in drying. It would diminish the amount of 

 energy calculated for the daily maintenance ration l)y about 10 calories or 0.02 of its 

 value." 



The results obtained with carbon are not regarded as final, but are given as a 

 progress report. 



The energy of the urine and the losses in drying it were also studied. In one case 

 it was found that the loss of carbon amounted to 0.269 per cent and that f)f nitrogen 

 to 0.224 per cent. On the basis of these figures and other data the author calculates 

 the proportion of these elements lost as ammonium carbonate and as indol and skatol. 

 From a consideration of the available data he concludes that "instead of sheep urine 

 being a mere solution of urea and hippuric acid, in this case fully half the total car- 

 bon j)robaV>ly existed in non-nitrogenous compounds. Other tests of sheep urine 

 from different feeds have given widely varying results, showing that there is no con- 

 stant relation of the nitrogenous and non-nitrogenous constituents." 



Determinations of the heat of combustion of sheep urine and a consideration of the 

 proV)able composition of the dried residue led to the conclusion that in estimating 



