Experiments on the Feeding of Sheep. 
197 
the diminution indicated by tlic approximate estimates given in 
the Table is less than we should have anticipated. 
It will presently be seen too, that, at least in these particular 
experiments, the anrovuit of increase obtained for a given amount 
of food consumed was much less during tlie second than during 
the first period of fattening. Even with pigs, it was found that 
there was a slight tendency to give a less amount of gross increase 
for a given amount of food consumed as the animal matured. 
This diminution was, however, in their case probably com- 
pensated for by the increased proportion of real dry or solid 
substance in the increase as they niatui'ed. Sheep also doubtless 
give a somewhat less aqueous increase as they fatten. But at 
any rate in these particular experiments, in which the animals 
lost weight during a part of the later period of feeding, there 
was then, compared with the earlier one, far too great a diminu- 
tion in the proportion of fp'oss increase to food consumed, to be 
compensated for by the slightly greater proportion of dry 
substance which that increase would contain.* 
That the amount of food consumed to a given live-weight 
should decrease as the animal matures, might be expected from 
the lessened proportion which the respiratory system will bear 
to the entire body the more the carcass increases and fattens. 
But, independently of this, it would be anticipated that the 
demands of the respiratory system would be less during the 
warmer months of Period 2 ; though, during the Avhole of 
Period 1 the animals were under cover, and, therefore, protected 
from inclement weather. 
We come now to a more direct consideration of the com- 
parative productiveness of the food in the Jiist and second periods 
of fattening, as illustrated by the approximate estimates given 
in Table 11. 
It appears that, in the case of every one of the six descriptions 
of sheep, there was nearly twice as much oil-cake ; in four out 
of the six considerably more hay-chaff, or its equivalent ; and in 
all cases much more, and in several more than twice as much, 
roots ; or, as shown in the two last columns, generally about 
IJ times as much dry substance of the mixed food, required to 
produce 100 lbs. of increase during the later than during the 
earlier period of feeding. 
It is not supposed that, under favourable circumstances, the 
productiveness of a given amount of food will diminish so rapidly 
with the progress of the animal from the fat to the very fat con- 
* For estimates of the character and composition of the increase during different 
periods of fattening, the reader is referred to our Report iu the last number of this 
Journal, vol. xxi., part 2. 
