Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo A.H. 201 (Final Revised) August 7, 1957
MIXED SUPPLEMENTS VS0 SOYBEAN MEAL FOR FATTENING CATTLE SELF-FED GROUND EAR CORN
T. W. Perry, R. L. Burns, M. T. Mohler and W. M. Beeson
Department of Animal Husbandry
Previous research (A0H. MLmeo 163, 1956) has indicated that the optimum ratio to mix ground ear corn and Purdue Supplement A for self-feeding cattle is 8 to 1, by weight. In this previous experiment, ratios of 4-1, 6-1, 10-1 and 12-1 of ground ear corn (corn-and-cob meal) to Supplement A were compared. Also, tests at Purdue comparing cottonseed meal, linseed meal and soybean meal or a mixture of the three for wintering cattle on corn cobs have shown these protein supplements may replace each other on a pound-for-pound basis. Experiments with urea on both growing and fattening rations have indicated that 33 percent of the protein requirement can be supplied by urea, provided the energy loss by substitution of urea is adjusted with corn or some other high-energy feed. Eighty-five pounds of ground corn plus 15 pounds of urea will replace 100 pounds of soybean oil meal.
The objectives of this experiment were as follows:
1.	To compare soybean meal with “Supplement A“ for balancing a ration for fattening cattle on ground ear corn.
2.	To compare cottonseed meal, linseed meal and soybean meal as sources of protein in “Supplement Aw for fattening cattle.
3.	To determine if approximately 85 pounds of corn and 15 pounds of urea can substitute for 100 pounds of soybean meal or linseed meal in a mixed supplement.
Experimental Procedure
One hundred fifty steer calves, which were raised in Texas, were delivered to Lafayette, Indiana, on August 26, 1956, at a cost of 23*5 cents per pound. Seventy-two of these steers were divided into 6 lots of 12 steers each, with an average beginning weight of 523 pounds.
The first day of the experiment, the cattle were turned into their respective lots and were given free access to mixed-grass hay. Four and one-half hours later, the feed bunks were filled with a mixture of ground ear corn (corn-and-cob meal) and protein supplement as indicated below:
Lot. I	- 8 parts ground ear corn to 1 part soybean meal.
Lot II	- 8 parts ground ear corn to 1 part Supplement A containing soybean
meal.
Lot III - 8 parts ground ear corn to 1 part Supplement A containing linseed meal.
Lot IV - 8 parts ground ear corn to 1 part Supplement A containing cottonseed meal.
Lot V	- 8 parts ground ear corn to 1 part Supplement A containing soybean
meal and 5 percent urea.
Lot VI - 8 parts ground ear corn to 1 part Supplement A containing linseed meal and 5 percent urea.