Mimeo A. H. 185 September 14, 1956
Purdue University Agricultural Experiment Station Lafayette, Indiana
One of the questions which the swine grower must decide on is how should corn be fed to growing-fattening hogs? Can maximum rate of gain and economy of gain be obtained when hogs are fed free-choice shelled corn and protein supplement from weaning to market or is it beneficial to feed a complete mixed ration for part or all of the growing-fattening period?
preliminary experiment conducted at Purdue last year showed that feeding a complete mixed ration on pasture resulted in a 12% increase in feed costs per 100 pounds of gain and an 11$ increase in rate of gain as compared to feeding a free-choice ration (A. H. Mimeo. 156). However, most of the increase in gain from feeding complete mixed rations came early in the experiment, because the pigs fed free-choice consumed too little protein supplement.
Recent studies at Nebraska (1954 and 1955) (1) in drylot have shown that the feeding of free-choice cracked corn and protein for all the feeding period or after the pigs reach 100 pounds is superior to feeding complete mixed rations from start to finish. Michigan (1955 and 1956) (2) reported no differences in gains when pigs were fed in drylot a complete mixed ration, free-choice ground corn or free-choice shelled corn and supplement. However, feed costs per 100 pounds of gain were $1.43 less for the pigs fed free-choice shelled corn and supplement ($9-08) compared to those fed a complete mixed ration ($10.51).
Illinois reported (1956) (3) that pigs fed complete mixed rations on pasture gained significantly faster than pigs fed free-choice on pasture. But comparable pigs fed in drylot gained at approximately the same rate. South Dakota (1956) (4) summarized a comparison of feeding free-choice and complete mixed rations both in drylot and on pasture as follows:	The main advantage of complete mixed rations com-
pared to free-^choice feeding seemed to be a slight increase in rate of gain; less protein supplement was consumed in the mixed rations but the cost of grinding and mixing offset this difference in feed costs.
In contrast, Iowa (1955) (5) has reported that pigs of similar weights making similar gains on the same amount of feed per pound of gain ate from 0.7 to 3 pounds of the same supplement per head daily. This article further states:	“With a free-
choice system of feeding, you*re relying on what the hog likes rather than what he needs to produce gains. Complete rations give the good efficient hog producer what he wants—controlled feeding, nutrition-wise and cost wise.* * * * * * * * 5*
The objectives of one experiment conducted on pasture and one experiment conducted in drylot were:
1. To determine if there is any advantage to starting pigs on complete mixed rations either on pasture or in drylot, then changing them to a ration of free-choice shelled com and protein supplement.
!• Nebraska 19th and 20th Annual Rooters Day. 1954 ?nd 1955*
2- Talk at American Farm Research Conference by Hoefer. 1955-Michigan Swine Day. 1956.
Illinois Swine Growers Day. 1956.
South Dakota Farm and Home Research 7:66.	1956.
5. Feed Age 5:36,	1955-
Weight to Change From Complete Mixed Rations to Free-Choice Rations Both on Pasture and in^I^yJLbt'
W. M. Beeson, J. H. Conrad, M. T. Mohler and T. W. Perrjy'
Department of Animal Husbandry