|Abstract or Summary
- The object of this study was to analyze the application of linear
programming techniques to ration formulation for feedlot lambs and
Three rations for feeder lambs were designed to study the application of linear programming techniques under varying ration constraints.
Rations studied were as follows:
iso-caloric rations with
three protein levels (14, 16, and 18% C.P.) as affected by diethyl-
stilbestrol (DES) application (none, oral, and implanted); iso-caloric,
iso-nitrogenous rations with varying protein sources (cull peas, alfalfa plus cull peas, urea, and clover seed screenings) as affected by a
commercial anthelmintic, Thiabenzadole, versus none; and iso-
nitrogenous rations of varying energy levels (.406, .426, and .446
megcal NE[subscript]p/lb.) on shorn and unshorn lambs.
In addition, a steer feeding trial was conducted in Central Oregon to compare feedlot performances of animals fed linear
programmed versus conventionally-formulated rations.
Trial results with feeder lambs indicate that rations
programmed to contain 16% C.P. produced better feedlot performances
(ADG, feed conversion, and cost/lb gain) than rations programmed to
contain either 14 or 18% C.P.
Also, oral administration of DES (3
mg/head/day) produced faster gains than implanted DES (3 mg).
Differences between performance in both cases failed to be significant at
the 5 percent probability level.
Lamb rations programmed to contain varying protein sources indicated that alfalfa pellets plus cull peas > cull peas > urea > clover
seed screenings when feedlot gains were compared. However, feed
conversion and cost/lb. gain figures favored the control ration which
was conventionally formulated. Of the programmed rations, that containing urea produced the least expensive gains.
This trial indicated
no economic value in worming lambs under these conditions. None of
the differences were statistically significant.
Trial results of rations compared as to varying energy levels
indicated that high energy linear programmed rations (.446 megcal
NE[subscript]p/lb.) produced more economical gains on less feed than lower
energy linear programmed rations (.406 and .426 megcal NE[subscript]p/lb.).
However, while not significant (P > .05), the control ration outperformed all linear programmed rations.
Trial results indicated that shorn feeder lambs outperformed unshorn feeder lambs.
Gains produced by linear programmed steer rations were less
than gains produced by the conventionally-formulated ration.
However, feed conversion and cost/lb. gain figures favored the linear
programmed rations during the 125-day trial.
Performance differences were not highly significant.
Linear programming techniques can be a valuable tool in formulating rations which meet specific ration constraints while maintaining
a least-cost solution.
Also, as shown by the foregoing data, linear
programming provides the mechanism for formulating rations for
specific requirements of experimental treatments.