Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo A.H. 144 April 29, 1955
Replacement of Soybean Meal with Urea and Corn for Fattening Cattle T. W. Perry and W. M. Beeson Department of Animal Husbandry
Ruminant animals are capable of manufacturing at least a part of their protein needs from a dietary source of inorganic nitrogen such as is supplied by urea or ammonia. The usual recommendation is that not more than one-third of the protein-equivalent be replaced by inorganic nitrogen. This recommendation has represented a very good estimate, but scientific evidence as to the maximum, or "safe level”, is lacking. Therefore, it was desirable to study the effects of feeding much higher levels of inorganic nitrogen to fattening cattle.
The objectives of this experiment were;
1. To determine whether a combination of urea nitrogen and corn can satisfactorily replace soybean oil meal, pound for pound, on a nitrogen-replacement basis in the ration of cattle being fed a fattening ration of ground corn, ground corn cobs, 3*5 pounds of Purdue Supplement A, and a simple mineral mixture.
2* If the first objective is true, to what extent can this replacement be made.
Expe rimental
Sixty Hereford Steers, 2 years of age and averaging 923 pounds, were divided into four lots of 15 each to be fed a fattening ration of ground corn, ground corn cobs, Supplement A, and minerals in drylot. One lot served as the check lot and received the ration indicated. The other three lots were fed urea-modifications of Supplement A such that a combination of urea and corn replaced the soybean meal contained in Supplement A by 1/3* 2/3 and 3/3, respectively, on a pound for pound and nitrogen replacement basis. (See Table I.)
At the completion of the 133-day fattening trial, each of the four lots was shipped to Chicago and sold separately. Hot dressed w®ights were obtained at the time of slaughter.