Research Progress Report 265 September, 1966
Effect of Methods of Preparation and Feeding of Corn on the Performance of Growing-Finishing Swine
R. A. Pickett and T. W. Perry 
Department of Animal Sciences

Summary
Pigs fed complete mixed rations gained significantly faster (P<.01) than those fed corn and supplement free choice, however, cost of gain was less for the free choice fed pigs. Expanded corn diets were utilized more efficiently than raw corn diets but produced an increased incidence of esophagogastric lesions compared to pigs fed normal raw corn. The number and severity of gastric lesions was also higher in pigs fed the more finely ground rations.

Feed Preparation
Research at Purdue has indicated that pigs fed rations prepared with finely ground or expanded corn gained more efficiently than those fed coarser feeds. In those experiments, however, there was a greater incidence of esophagogastric ulcers and associated lesions in the pigs fed gelatinized corn or finely ground raw corn.
This experiment was designed to further investigate the influence of ration particle size and method of feeding on the performance and incidence of stomach lesions in growing-finishing swine.

Procedure
One hundred sixty crossbred Hampshire -Yorkshire pigs weighing an average 56 pounds were allotted to 10 pens on the basis of sex, weight and litter. Six lots of pigs were fed corn and supplement free choice and four lots were fed complete mixed rations (Table 1). The complete mixed rations contained 16 percent protein to an average pig weight of 100 pounds at which time the protein level was reduced to 13 percent.

Treatments for this experiment were:
1. shelled corn plus supplement - free choice (FC), 2. coarse expanded corn plus supplement - FC, 3. medium grind (shelled) corn plus supplement FC (Corn ground through a 1/2" hammermill screen), 4. medium grind expanded corn plus supplement - FC, 5. fine grind (shelled) corn plus supplement - FC, (Corn ground through a 1/16" hammermill screen), 6. fine grind expanded corn plus supplement FC, 7. medium grind (shelled corn) in complete mixed ration (CMR) - corn same as treatment 3, 8. medium grind expanded corn -CMR - corn same as treatment 4,	9. fine grind shelled corn - CMR - corn same as treatment 5, 10. fine grind expanded corn-CMR - corn same as treatment 6.
PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana