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Natural Sciences Education Abstract - Animal Science Education

Taurus: A Ration Formulation Program for Beef Cattle


This article in NSE

  1. Vol. 42 No. 1, p. 145-159
    Received: Sept 19, 2011
    Published: November 7, 2013

    * Corresponding author(s): jwoltjen@ucdavis.edu
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  1. J. W. Oltjen *a and
  2. A. Ahmadia
  1. a Dep. of Animal Science, One Shields Ave., Univ. of California, Davis, CA 95616


Taurus is used to formulate and evaluate rations for growing or breeding beef cattle (Bos taurus). It provides a practical feed ingredient loading utility, a flexible feeds library and editor, and a module to estimate feed energy values. It also includes a beef cattle growth simulator. To formulate a least cost ration, the user inputs animal and feed descriptions. The program supports both metric and English measurements. Taurus uses National Research Council (NRC) beef nutrient requirements for energy, protein, calcium, and phosphorus, but the user can edit existing requirements or add new ones. Feeds are selected from a standard library of 707 feeds and their nutrient analysis. For each feed, the user can specify a price and a minimum or maximum. The user can add new feeds or edit existing ones. Feeds can be grouped so that the ration may have a minimum or maximum group constraint. Similarly ratios of nutrients can be defined and constrained. Output is cost and performance, feeds used and nutrient analysis, and price ranges for feed used or not used. A delivery module specifies feed loading and unloading batches. The Profit Projection module projects performance of growing and finishing cattle. Profit Projection allows up to five feeding rations and/or periods; it predicts live weight, quality grade, yield grade, and days on feed. Outputs are a feedlot closeout and daily performance including projected costs and returns. The FeedTag module predicts the feed energy based on regressions on feed crude protein, ether extract, ash, and crude fiber.

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Copyright © 2013. Copyright © 2013 by the American Society of Agronomy