472 



Agricultural Chemistry, — Pig Feeding. 



No. 1 pig was, compared with the others, a large-framed growing 

 animal ; and he was, moreover, a very obstinately masterful and 

 selfish one, requiring the whip more frequently than any other of 

 the entire Series. It is probable, therefore, that in spite of the 

 care that was taken, he managed to secure more than his share of 

 the best adapted food ; and, besides this, he doubtless retarded 

 the progress of the other two pigs by disturbing their repose and 

 comfort. 



In Pens 5, G, 7, and 8, we have, instead of the Bean and Lentil 

 mixture, Indian-corn meal as the ad libitum food ; which, it will 

 be borne in mind, contains much less of nitrogen, but much 

 more of the non-nitrogenous constituents than the former. 



In Pen 5 the Indian meal was given alone, ad libitum of course. 

 One of the pigs on this food gained more than 2 lbs. a day during 

 the first fortnight of the experiment ; but the other two only 

 about half as much. Before the end of this first period, however, 

 it was observed, that this fast gaining pig, and one of the others, 

 namely. No. 3, had large swellings on the side of their necks ; . 

 and that at the same time their breathing had become much 

 laboured. It was obvious that the Indian corn meal alone, was 

 in some way a defective diet ; and it occurred to us, that it was 

 comparatively poor both in nitrogen and in mineral matter, — 

 though we were inclined to suspect, that it was a deficiency of 

 the latter, rather than of the former, that was the cause of the ill 

 effects produced. We were at any rate unwilling so far to dis- 

 turb the plan of the experiments as to increase the supply of 

 nitrogenous constituents in the food ; and accordingly determined 

 to continue the food as before, but, at least, to try the effect of 

 putting within the reach of the pigs, a trough of some mineral 

 substances, of which they could take if they were disposed. The 

 mixture which was prepared was as follows : — 20 lbs. of finely 

 sifted coal ashes, 4 lbs. of common salt, and 1 lb. of superphos- 

 phate of lime. A trough containing this mineral mixture was 

 put into the pen at the commencement of the second period, and 

 the pigs soon began to lick it with evident relish. From this 

 time the swellings or tumours, as well as the difficulty in breath- 

 ing, which probably arose from the pressure of the former, began 

 to diminish rapidly. Indeed, at the end of this second period 

 the swellings were very much reduced, and at the end of the third 

 they had disappeared entirely. No. 1 pig, which increased the 

 most of the three during the first, third, and total periods of the 

 experiment, it is seen only gained 6 lbs. during the second 

 period ; he was, however, during that time the worst affected by 

 disease as described above. As, however, his apparent increase 

 was so great during the first and third periods, it is probable, 

 that part at least of the deficiency in the intermediate period, was ^ 



