ANIMAL NUTRITION DISCUSSION AT DUNDEE 419 



the starch equivalent considered by Kellner to be necessary for 

 the maintenance of the cattle of the size used has been deducted. 

 This leaves a figure which represents the starch equivalent of 

 the ration which is available for maintenance in each case and 

 one would anticipate that the daily gain would be in propor- 

 tion to this figure. If this were so the coconut cake lot should 

 have made about 4 per cent, greater gain than the linseed 

 cake lot and the bran lot about 88 per cent, of the gain of the 

 linseed cake lot. Actually the bran lot made 89 per cent, of 

 the gain of the linseed cake lot, which must be regarded as 

 extremely close agreement with expectation ; but the coconut 

 cake lot made 16 per cent, less gain than the linseed cake lot. 



The second point advanced for discussion is a means of 

 establishing a relationship between commercial values of 

 different feeding stuffs. Most experiments stop short at deter- 

 mining the relative value of feeding stuffs at the prices current 

 when the experiment is conducted ; consequently there is some 

 difficulty in applying the results, because the market prices of 

 feeding stuffs fluctuate and accordingly change in relation to 

 each other. The chief difficulty arises from the fact that the 

 price of a feeding stuff has to cover two things of importance 

 to the farmer, namely the consuming value and the manurial 

 value. An attempt to deal with this difficulty may be given in 

 concrete form. In seasons 1909-10 and 1910-11, a series of 

 cattle-feeding experiments was undertaken to determine the 

 value of soya bean cake by comparing it with linseed cake in 

 the winter feeding of cattle. A number of lots of cattle con- 

 sisting altogether of seventy-two animals were equally divided 

 and fed exactly alike in all respects except that the one half 

 got 4 lb. of linseed cake per head per day and the other received 

 4 lb. soya bean cake. In this way 6 tons i8f cwts. of the 

 two cakes were consumed. The increases were as follows : 



Live Weight increase. Cost per cwt. 



cwt. qr. lb. s. d. 



Linseed cake 84 1 24 37 %\ 



Soya bean cake .... 78 o 5 35 5I 



The difference in cost thus amounted to 2s. id. per cwt. live 

 weight increase in favour of the soya bean cake or 255. id. per 

 ton of that food consumed. 



The linseed cake cost £g 5s. per ton and the soya bean cake 

 £6 155.; when the value of their manurial residues, namely 



