208 THE COMPLETE GRAZIER. BOOK i. 



" Not only does the first series increase more rapidly than the second, 

 but it appears that the animals make a better use of their food, and 

 digest and assimilate a larger quantity. Thus, for example, during the 

 second period, the first series require 467 lb. of nutritive matters to 

 produce a gain of 100 lb. of live weight, while the second series require 

 906 lb. ; and this corresponds also with the composition of the dung, for 

 Crusius finds that of the first series to contain daily 1 lb. of solid matter 

 less than that of the second. 



" It is clear, then, that the addition of fatty matters to the food is 

 useful, not only by supplying that necessary ingredient, but also in so 

 far as it promotes the assimilation of its other constituents ; but it still 

 remains to be determined whether it will pay. Into the consideration 

 of this point also Crusius enters very minutely, and shows, from the 

 actual cost of the food and prices realised in the market, that the profit 

 derived from each pound of live weight acquired by the animals 

 amounted to l^d. It must be borne in mind, also, that the question 

 of economy was not considered in fixing the nature and quality of the 

 food, the object being to effect the most complete comparison between 

 substances differing only in the oil they contained, and hence it became 

 necessary to employ oil itself, of which the cattle, in the course of the 

 experiment, consumed about two cwt., at a cost of 41. 10s., while, had it 

 been possible to disregard the composition of the food in other respects, 

 it might have been supplied at one-tenth of this price. 



" These experiments, although they by no means exhaust this sub- 

 ject, are peculiarly interesting because they show that a positive 

 advantage is gained by increasing the quantity of fat in the food, and 

 they justify the preference which the feeders of this country have 

 always shown for oil-cakes of different kinds. They open up also the 

 question of whether oil itself may not be at times an economical food. 

 It is perfectly conceivable that there may be a mixture of foods the 

 digestibility of which may be so greatly increased by the addition of a 

 comparatively small quantity of oil as to render its use remunerating. 

 We have been informed, indeed, that linseed oil was used to some extent 

 in feeding sheep during last winter, and with excellent results." 



In the Journal of the Royal Agricultural Society, Vol. XXV., second 

 series, 1889, Mr. F. I. Cooke details a series of experiments on the 

 value of the oil in linseed-cake as food for stock. He commences : 



"It is very well known that owing to modern improvements in 

 machinery, and an increase in the value of oil, as compared with the 

 large reduction in price of linseed-cake, the latter product contains now 

 a less amount of oil than was commonly found in it a few years ago. 

 A diminution in the percentage of oil in a cake is necessarily 

 accompanied by an increase in the other constituents, and arguments 

 have recently been advanced by German and other authorities tending 

 to show that a cake low in oil may have a feeding value equal if not 

 superior to one containing a larger amount of oil. On the other hand, 

 many of our leading agricultural chemists have continued to put a 

 much higher value per unit, for fattening purposes, upon oil than upon 

 any other nutrients in a cake. Considering, therefore, this prevailing 



