Degree Type

Dissertation

Date of Award

1981

Degree Name

Doctor of Philosophy

Department

Animal Science

Abstract

The data base for this study included results of experiments conducted during the course of the project and data available from the literature. These data were used to obtain quantitative information describing supplemental dietary fat's effects on body weight gain and efficiency of feed utilization of growing turkeys. Evaluation of the data showed a significant relationship between level of supplemental fat and turkey growth. Weight gain and feed efficiency were improved 0.84% and 1.65%, respectively, for each one percent fat;A model was derived to determine under alternative levels of fat usage, ration ingredient costs, and turkey market prices the economically feasible situations for supplemental dietary fat usage in growing turkey diets. The model considers the dietary interactions associated with fat addition in terms of corn and soybean meal adjustments to balance protein and energy requirements when fat is used;The model can be coupled to existing least-cost ration formulation programs used by turkey producers or feed manufacturers to allow for immediate feedback regarding the economic feasibility of fat addition. Two potential limitations exist in applying this model. The validity of the information obtained from the model will be limited by the appropriateness of the input costs in each specific situation and by the accuracy of the published data regarding the responses of turkeys to supplemental fat levels;Given the limitations of the production function model, a predictive equation was generated using a stepwise multiple regression procedure to more adequately assess the economic benefits of using supplemental fat. The multiple regression model is more efficient to use than the production model because the regression equation directly measures return above feed cost whereas the production function model measures return above feed cost indirectly. The major advantage of the prediction equation is that regression coefficients calculated for the input variables measure the relative importance of the input-output relationships and serve as a basis for determining the economic effectiveness of fat supplementation.

DOI

https://doi.org/10.31274/rtd-180813-5280

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Albert Kagan

Language

en

Proquest ID

AAI8209136

File Format

application/pdf

File Size

81 pages

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