470 



Agricultural Chemistry. — Pig Feeding. 



ences in the progress of the pigs allotted together in the same 

 pen and with the same food, arise from general differences of 

 constitution ; and if the irregularity in this respect were equal 

 in every pen, it would certainly be an advantage, for our object 

 is not to show the extraordinary increase of picked animals, but 

 the probable average result obtainable from pigs which have 

 been bred or selected for fattening with ordinary care and judg- 

 ment. Indeed, as already observed, our chief object in the allot- 

 ment was to get a variation of quality within each pen with 

 similarity between pen and pen in this respect ; and the observa- 

 tions which were made at the end of the experiment, when the 

 pigs were killed, clearly showed, that whilst on the same food, 

 some had increased considerably in frame as well as flesh and 

 fat, others had apparently accumulated fat almost exclusively. 

 These variations of result, then, we attribute chiefly to the dif- 

 ferent constitutional tendencies of the animals. But, at the same 

 time, though very great care was taken to prevent it, we do not 

 pretend to say, that where the limited food was very decidedly 

 of better quality than the remainder, the stronger animals did not 

 sometimes obtain an advantage over the weaker ones. Perhaps 

 in one or two instances, therefore, one pig in a pen may have 

 done better, and another worse, than would have resulted from a 

 due share of the allotted food. Supposing this to have been the 

 case, however, it is still by no means certain that the results indi- 

 cated by the whole pen are on this ground unfair as regards the 

 effects of the total food supplied to it ; for, although one pig may 

 have increased much more than another upon a supposed equal 

 diet, the gain of each may, in fact, be only commensurate with 

 the food actually consumed in each case ; and thus, with great 

 variation in the different pigs, with diets from one cause or an- 

 other themselves really different, the total increase of the entire 

 pen may still indicate, with some truth, the effects of the total 

 food consumed in it — the smaller increase of the one pig with a 

 deficient share of food being compensated by the larger gain of 

 the other upon at the same time a larger and better share of food. 



But to turn to the figures of the table. In the first 4 pens the 

 Bean and Lentil mixture is given ad libitum ; in Pen 1, without 

 any other food ; and we find that, with this very highly nitro- 

 genous food alone, there is nearly as high a total gain, and a 

 greater regularity of progress among the different pigs, and also 

 throughout the several periods and the total period of the experi- 

 ment, than in any other pen. 



In Pen 2, besides the Bean and Lentil meal, there was an allow- 

 ance of 2 lbs. of Indian-corn meal per pig per day ; which, as we 

 have said, contains much less of nitrogen, but more of the non- 

 nitrogenous, starchy, and fatty matters, than the Beans and Len- 



