Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo A.H. 226 April 25, 1958 (Progress Report)
CORN SILAGE VS. SORGHUM SILAGE
WITH VARIOUS ANTIBIOTICS FOR FATTENING HEIFERS*
T. W. Perry, Marshall Davis and W. M. Beeson Department of Animal Husbandry
Several years research conducted at Purdue has shown that a ration of a full feed of corn silage, 3.5 lb. of Supplement A, and free choice minerals, is an efficient and economical fattening ration for growing and fattening beef cattle.
This ration is especially well adapted to cattle which are yearlings or older at the time they are started in the feedlot. Calves wall gain rapidly and efficiently on such a ration but may lack the market finish desired at the end of a 180 day feeding period due to the fact that a larger portion of their feed goes for growth than is the case in older cattle. Also, it was at this Station that the consistent beneficial effect from the feeding of an antibiotic to cattle on a predominantly roughage ration was reported.
The objectives of the research reported in this mimeograph were:
1,	To compare the feeding value of corn silage with that of sorghum silage (Atlas) for calves which were fed a full feed of silage, 3*0 lb, Purdue Supplement A, and free choice minerals,
2,	To compare a mixture of antibiotics (aureomycin, terramycin, bacitracin and penicillin) with a single antibiotic (aureomycin),
3,	To study the effect of adding corn to the corn silage and sorghum silage rations (listed in objective 1) after an initial feeding period of 98 days.
One-hundred-fifty Hereford heifer calves, which wTere raised in Oklahoma, were purchased at an average price of &23,25 per hundredweight and delivered to Lafayette, Indiana. Seventy-two of these calves, averaging 568 pounds, were used for this experiment. The calves were divided equally, on the basis of weight, type and general thriftiness into 6 lots of 12 heifers each.
There were two phases of this experiment. In the first phase of the experiment a mixture of antibiotics was compared with a single antibiotic, when fed with a full feed of sorghum silage or of corn silage, plus 3,0 lb. Supplement A, and free choice minerals. In the second phase all lots were fed a single antibiotic, and levels of shelled corn were added to the silage rations.
Aureomycin was furnished by American Cyanamid Company, Pearl River, New York; Bacitracin-Penicillin by Commercial Solvents, Terre Haute, Ind.j and Terramycin by Chas. A. Pfizer and Co., Terre Haute, Indiana.
Experimental Procedure