528 Agricultural Chemistry, — Pig Feeding. 



Reviewing then, as a whole, the results of these Three Series 

 of experiments with Pigs, and carefully considering the bearing 

 of the various circumstances v/hich must influence our reading 

 of the actual figures of the Tables relating to them — we think it 

 cannot be doubted, that here, as we have already shown in the case 

 of our Sheep experiments, the evidence is very clear, that it is the 

 nitrogenous rather than the nitrogenous constituents of the foods, 

 that have been the gauge of, or fixed the limit to — consumption. 



We now come to the question of the relationship respectively, 

 of the nitrogenous and of the non-nitrogenous constituents of the 

 food, to the amount of increase in live iceight obtained in the 

 fattening Pig. This point is illustrated in Talbles XXV., XXVI., 

 and XXVII., which give the amounts of fresh food, or of its various 

 constituents, which were consumed to produce 100 lbs. increase in 

 live iveight of animal.^' In considering these Tables, we must of 

 course, as before, read the indications of the actual figures, as modi- 

 fied by the obviously different capacities for the purposes of the 

 animal economy, of the substances the amounts of which they in 

 each case represent. We must remember too, that as in the Tables 

 showing the relationship of consumption to respiration, the 

 figures included also the amounts which served to increase the 

 weight of the animal — so now, in these Tables professing to 

 show the relationship of the increase to the constituents consumed, 

 the figures at the same time include the amounts which have 

 been expended in the respiratory process. And further, we 

 should recal to mind the fact, that even the increase itself, will 

 represent different amounts of total dry or of nitrogenous 

 substance, expended to produce it, according to the amounts 

 respectively, of fat or of flesh, which it may contain. 



If we cast the eye down the columns of non-nitrogenous sub- 

 stance consumed, and more particularly those of the total organic 

 matter, in these Tables (see Division 2, Tables XXV., XXVI., 

 and XXVII.), we see, with but few exceptions, a very strikingly 

 close coincidence in the amounts of these, required to produce 

 100 Tbs. gross increase throughout these three Series of experi- 

 ments with Pigs. Some of the exceptions, such as those where 

 a large quantity of Bran was used, are at once explained by a 

 consideration of the more obvious qualities of that food ; and 

 some of the minor differences, by that of the different respiratory 

 and fat-forming capacities of those portions of the foods which 

 would be digestible and available for the purposes of the animal 

 economy. Turning now to the adjoining columns in these 

 Tables, those of the nitrogenous substance consumed to produce a 

 given weight of increase throughout these three Series, we find the 

 amount of it as strikingly various as that of the non-nitrogenous 



* See also Diagram II. 



