14 BULLETIN 752, U. S. DEPARTMENT OF AGRICULTURE. 
per day. There was no consistent significant difference between 
small pigs and large pigs in this connection. In pasturing alfalfa 
approximately to its carrying capacity, a daily gain of 15 to 20 
pounds per acre would be a conservative estimate if the supplemen- 
tary corn ration were as high as 2 per cent. 
Data on carrying capacity are furnished by 34 lots. With 23 of 
these the average carrying capacity was between 2,001 and 3,000 
pounds per acre for the pasture period. Usually the alfalfa pasture 
will support a somewhat greater live weight of large pigs than of 
small ones. The carrying capacity is, of course, higher in midsum- 
mer than in spring or early autumn, because of the more rapid 
growth of the crop in warm weather. In the extreme south- 
western section of the country, however, a period of slow growth 
occurs during the hottest part of the summer. An average carrying 
capacity of 2,500 pounds per acre would be a safe estimate on which 
to base alfalfa pasturing enterprises if the pasture were supple- 
mented with as much as a 2 per cent ration of corn. The carrying 
capacity increases rapidly with increased grain allowance. 
Of the 44 lots furnishing data on the grain requirement per hun- 
dred pounds of gain, 32 required between 200 and 300 pounds. In 
general, the grain requirement increased with the size of the hogs 
and the size of the grain ration. With pigs averaging less than 125 
pounds at the beginning of a 60-day to 90-day pasturing period, and 
fed a supplementary corn ration of about 2 per cent, the grain re- 
quirement per hundred pounds of gain should not exceed 300 pounds, 
and with very favorable conditions it should be as low as 250 pounds. 
The rate of gain is influenced by the size and character of the hogs, 
the abundance of the alfalfa, and the size of the corn ration. The 
average daily gain per pig in the 44 lots on alfalfa pasture supple- 
mented with corn ranged from 0.30 pound to 2.24 pounds, the latter 
being secured with a lot of thirty-three 139-pound pigs on pasture for 
only 19 days and fed a corn ration of 6.95 per cent. Of the 44 lots, 
11 made average daily gains ranging from 0.30 to 0.50 pound per pig; 
16, from 0.51 to 0.75 pound; 9, from 0.76 to 1 pound, and in the re- 
maining 8 lots the average daily gain per pig ranged from 1.01 to 
2.24 pounds. These figures, covering the diversity of conditions in 
the 44 tests, are of value, as they will apply ina general way to mixed 
lots of. pigs, of which many are pastured by irrigation farmers. With 
such lots the daily gain per pig on alfalfa pasture supplemented with 
corn can be expected to average from 0.50 to 1 pound, small pigs and 
light rations producing the lower gains and large pigs and heavier 
rations producing the higher gains. Of the 44 lots, 16 had average 
initial weights of less than 50 pounds per pig. The average daily 
gains of these 16 lots ranged from 0.30 to 0.67 pound. There were 11 
