FEEDING OF ANIMALS. 291 



amount of total dry or solid matter, of nitrogenous substance, 

 of fat, and of mineral matter, determined in it. The other 

 was then fed for a period of ten weeks, on a mixture consist- 

 ing of — bean-meal, lentil-meal, and bran, each 1 part, and 

 barley-meal 3 parts, given ad libitum. It was then weighed, 

 killed, and its composition determined as in the case of the 

 other animal. In fact, the object of the experiment was, to 

 determine the composition of a " store " and of a "fat " pig, 

 and to estimate the composition of its increase whilst fatten- 

 ing ; and the data thus provided have formed the basis of the 

 estimate of the fat in the increase, not only in the case of 

 experiment 1, to which they directly apply, but in that 

 of each of the other eight experiments, the results relating to 

 which are recorded in the table. On this point it may be 

 observed that, taking into consideration the weight and con- 

 dition of the animals at the commencement, the character of 

 the foods, the length of the fattening period, the proportion 

 of increase upon the original live-weight, and the final con- 

 dition of the animals, it may perhaps be concluded, that the 

 tendency of error in the calculations would be to give the 

 proportion of fat in the increase somewhat too high in experi- 

 ments 2 and 3, and somewhat too low in experiments 6, 7, 8, 

 and 9. In experiments 4 and 5, however, the animals were 

 the fattest in the series ; and it will be seen further on, that 

 the high estimates of fat in the increase in their case are pro- 

 bably not too high — indeed, in experiment 5 even somewhat 

 too low. 



It might be supposed that, at any rate in the case of 

 experiment 1, the results would be admirably adapted for our 

 present purpose. But that experiment was made in 1850, 

 that is nearly forty-five years ago, and before we had acquired 

 sufficient evidence against the view then prevailing — namely, 

 that the increase of the fattening animal was largely depend- 

 ent on the richness of the food in nitrogenous constituents ; 

 and everybody having experience in the fattening of pigs will 

 admit that, in this case, the food was much more highly 

 nitrogenous than is recognised as most favourable for the 

 fattening of the animal. In fact, it is seen that the propor- 

 tion of the crude non- nitrogenous to 1 of crude nitrogenous 

 substance in the food, was only 3.6 instead of about 6, as in 

 barley-meal. There was, therefore, an excess of nitrogenous Excess of 



Substance Consumed. nitrogenous 



Referring to the middle division of the table, the calculated in the food. 

 results show that, for 100 increase in live-weight, 100 of 

 nitrogenous substance was consumed in the food. Of this, it is 

 estimated that only 7.8 parts were stored up in the increase, 

 leaving 92.2 parts available for the possible formation of fat. 



