From sustag@beta.tricity.wsu.eduFri Jul 5 22:21:10 1996 Date: Thu, 4 Jul 1996 11:56:42 -0700 (PDT) From: "Tom Hodges (moderated newsgroup)" To: Principles of Sustainable Agriculture Subject: GRAZE for Windows Date: Tue, 25 Jun 96 15:38:34 EDT From: "Otto J. Loewer" Subject: GRAZE for Windows CC: oloewer@agen.ufl.edu Reply-To: "Otto J. Loewer" With apologies for those who have received this from more than one source.... Free beef-forage Selective Grazing Software Announcement ____________________________________________________________________________ I am pleased to announce to you that the beef-forage selective grazing research model "Graze for Windows" is now available for downloading through the World Wide Web at the following URL address: http://www.agen.ufl.edu. This the home page for the Agricultural & Biological Engineering Department at the University of Florida. The route to follow is "Software for PC's", "Graze ", and click on either the Windows or DOS title for downloading. What is In It for You and Others in the Beef-Forage Industry? ____________________________________________________________________________ _____ The Graze for Windows model provides a framework for integrating the knowledge and experiences of producers, animal scientists, plant scientists, soil scientists, economists, engineers and others interested in some facet of the animal grazing system. Graze is also part of the focus of a new regional Information Exchange Group: sera-ieg-21: Use of Forage-Animal Models in Resource Management The objectives of this U.S. Information Exchange Group are: 1. Provide a mechanism for researchers and extension personnel to expand the use of computer models in decision support systems for integrated resource management. 2. Seek ways to transfer technology associated with the Graze model to regulatory agency personnel, policy makers, commodity representatives and grazing land managers. 3. Continue to evaluate and improve the Graze model through field and laboratory experiments and enhancement of its fundamental logic through feedback from expanded communication. Updated information concerning the activities of this group may be obtained through the following World Wide Web addresses: http://www.bae.uky.edu/~lturner/sera-ieg.htm http://www.forages.css.orst.edu/ (Projects -> Regional -> sera-ieg-21) How Can Graze be Used? ____________________________________________________________________________ _____ Graze for Windows can be used in many ways: 1. Graze can be used directly to predict values such as body weight, daily weight gain, amount of forage consumed, forage availability, etc., within a given beef-forage grazing scenario. 2. Graze can be used to compare various performance measures of several different scenarios (for example, the Scenario A resulted in a greater weight gain per hectare than Scenario B). 3. Graze may be used to generate a predicted response to a change in inputs that may influence research or management understanding. For example, how will animal performance change if a plant input parameter was altered (reflecting the possible impact of a forage breeding program) or if a different fertilizer schedule was used (reflecting a different management system)? 4. The Graze input database structure may be used by a field or laboratory researcher to provide guidance for placement of laboratory or field data into a form that can be directly used by others via a computer model. Examples include the Graze input databases related to plants, animals and soils. 5. Graze can be used as the analytical structure that mathematically ties together the many biological processes that composes the beef-forage system. Thus, after researchers with different specializations make independent contributions (see "4" above), others (to include researchers, extension specialists, producers, students, etc.) can evaluate the total system to meet their individual needs. What is Needed in Graze and What are Your Opportunities for Participations in Its Development? ____________________________________________________________________________ _____ Graze is a research model. Therefore, it needs inputs from a number of sources including: 1. Experiences of those who use Graze to investigate management of grazing systems and are willing to help make later versions of the model even better. 2. Those who are willing to add to the Graze input databases for forages, animals, soils and weather inputs in order to expand applicability of the model, and then share their information with others. 3. Those who are interested in using scientific data to calibrate the default inputs for forages, animals and soils, and to share their inputs in later versions. 4. Those who wish to enhance the fundamental Graze logic. Who Might be Especially Interested? ____________________________________________________________________________ _____ 1. Grazing research teams at universities, government agencies and private consulting firms who are interested in a comprehensive systems approach to grazing. 2. Researchers and graduate students interested in a particular part of Graze, perhaps as a thesis project. 3. Producers who want to "test the model" at their locations to see how well it meets their expectations, and to also help "work the bugs" out of the model (all models have them!) and to help make the model more "user friendly" in later versions. Realistic Expectations ____________________________________________________________________________ _____ In no way does the Graze for Windows software and supporting material claim to address all the issues associated with beef-forage grazing systems. Hopefully, Graze does offer a type of research "road map" that allows those interested in beef-forage grazing systems to have a clearer picture of how this system functions and to identify the areas where a greater understanding of the system is needed. Certainly, there are "bugs" in Graze for Windows. As a research model, it is expected that occasional updates will be needed, first to correct known errors and second to add mathematical structure needed to enhance the capabilities of the model. The World Wide Web will be the source of update information. What is Graze for Windows all About? ____________________________________________________________________________ _____ Graze for Windows is a research model; that is, this model was developed to provide a research structure for analyzing beef-forage grazing systems. While results from Graze have compared favorably with those observed under field conditions, the model has not been thoroughly evaluated for all possible combinations of input conditions. Likewise, Graze utilizes a large number of input parameters, and not all of these have been included in the Graze input data base (for example, more information on different soils are needed) nor have all been calibrated where research information was not complete. Nevertheless, Graze does a reasonably good job of predicting grazing performance. The model will improve as researchers add to its input data base, refine its internal mathematical logic, and add to its capabilities. While Graze is a research model, it is sufficiently "user friendly" to be used as a management tool as long as the user recognizes the various assumptions that are part of the model. The user of a program like Graze must understand that the effective utilization of software in making significant management decisions requires considerable effort and study. Not all software is created equal; that is, each software package contains a set of assumptions that define the boundaries where the program can be used with reasonable confidence. Graze is a very large and sophisticated model. Accordingly, its predictions are based on a very large set of mechanistic relationships. Inquiries ____________________________________________________________________________ _____ Inquiries should be submitted in writing or e-mail to the following address for referral as appropriate: 1. For questions about the mathematical-logical relationships, inputs and assumptions used in Graze and Graze for Windows , contact: Otto J. Loewer, Professor & Chairman, Agricultural & Biological Engineering Department, P.O. Box 110570, Rogers Hall ,University of Florida, Gainesville, FL 32611-0570, email: oloewer@agen.ufl.edu , voice: 352-392-1864, fax: 352-392-4092 After July 1, 1996: Dean of Engineering, Room 4183 Bell Engineering Center, University of Arkansas, Fayetteville, AR 72701 USA, email: ojl@engr.uark.edu, voice: 501-575-3054, Fax: 501-575-4346 2. For questions about the inputs to the DOS version of Graze and the availability of the Graze User Guide and Case Study publications, contact: Lucas D. Parsch , Associate Professor, Agricultural Economics & Rural Sociology Department, University of Arkansas,Fayetteville, AR 32701, email: lparsch@comp.uark.edu, voice: 501-575-2323, fax: 352-575-5306 3. For questions about the Windows structure of Graze and any difficulties encountered in downloading any of the Graze programs via the World Wide Web, contact: Larry W. Miller, Engineer, Agricultural & Biological Engineering Department, P.O. Box 110570, 28 Rogers Hall, University of Florida, Gainesville, FL 32611-0570, email: miller@agen.ufl.edu, voice: 352-392-7691, fax: 352-392-4092 4. For questions about SERA-IEG-21: Use of Forage-Animal Models in Resource Management, contact: Larry Turner, Professor, Biosystems and Agricultural Engineering Department, University of Kentucky, Lexington, KY 40546. email: lturner@ca.uky.edu, voice: 606-257-3000, Fax: 606-257-5671. Graze Availability and Documentation ____________________________________________________________________________ _____ In 1995, two publications were developed to accompany the Graze DOS-based software. The first was the Graze Beef-Forage Simulation Model: User's Guide (L.D. Parsch and O.J. Loewer, editors, 1995) and the second was the Graze Beef-Forage Simulation Model: Case Studies (O.J. Loewer and L.D. Parsch, editors, 1995).. These publications, along with diskettes of Graze, are available for a $4 (U.S.) handling fee from: Agricultural Publications, AGRI 110, University of Arkansas, Fayetteville, AR, 72701 Downloading via the Internet ____________________________________________________________________________ _____ The DOS version of Graze and Graze for Windows are both made available free of charge via the Internet at the following addresses: Agricultural & Biological Engineering, University of Florida, http://www.agen.ufl.edu, (Software for PC's -> Graze -> Graze) Forage Information System (Oregon State University), http://www.forages.css.orst.edu/, (Resources -> Media -> Software -> Animals) Instructions for downloading are as follows: Download the file into a separate subdirectory such as "tempag". Use binary FTP or any similar file transfer procedure with which you are familiar. If the file ends in .EXE (makegraz.exe), it is a self-executing unzip. If the file ends in .ZIP, it must be unzipped by running "pkunzip" (gw300.zip). The temporary directory will then contain all of the files in the distribution package. Change to that directory and read the readme file for overwrite cautions and then execute "setup.exe". For additional protection, set all of your original *.dLL and *.vbx file attributes to read only, or copy them to a different directory, or rename them. "setup.exe" will ask where to install the Graze subdirectory on your system. "tempag" may then be removed or copied to diskettes for a backup. It is not necessary to save the original .zip or .exe file, only the packaged distribution files. Graze requires Windows Version 3.1 or Win95 or Windows "nt" and a 386 processor. Loading procedures require at least 3MB. History and Model Structure ____________________________________________________________________________ _____ Graze is a relatively large (17,000 lines of code) and complex dynamic mathematical research model that simulates the daily performance and interactions associated with beef-forage grazing systems. Graze has its roots in the "beef" model developed at the University of Kentucky in the late 1970's. Agricultural scientists from 25 states have assisted in its development over the years through three regional research projects (nc-114: Forage Production and Utilization Systems as a Base for Beef and Dairy; S-156: Simulation of Forage and Beef Production in the Southern Region and, most recently, S-221: Development of Profitable Beef Forage Production Systems for the Southern Region). Graze is composed of three major submodels involving forages, beef animals, and the forage-animal selective grazing interface. At the beginning of a simulated day, Graze computes the forage that will be grown over the next 24 hours as influenced by temperature, rainfall, soil nutrients, soil moisture availability and the existing growth status of the plant. After each 15 minute segment of simulated time, Graze computes the quantity of forage, if any, that the beef animal consumes. This quantity reduces the level of dry matter available on the field. The consumed dry matter is converted within the animal to various tissues and either chemical or thermal energy, with some of the material eventually exiting the body as fecal material, urine or heat. Chemical energy and nutrients are converted to various body components, the rate and quantity being a function of the physiological state of the animal at the time the forage is consumed. Forage intake may be restricted because of physical fill, thermostatic regulation, chemostatic regulation and rest requirements. Within Graze, the animal selects forage for consumption based on the assumption that the animal attempts to maximize its digestible dry matter intake rate. Graze is a very complex dynamic simulation model written in fortran. Graze was developed initially as a mainframe research model and was modified to be run on a microcomputer. A moderate knowledge of microcomputers, spreadsheets and Windows is needed to effectively use the model. It contains approximately 17,000 lines of code and may be executed on a 386-based microcomputer (or higher) equipped with a math coprocessor. How Graze for Windows differs from the dos Version of Graze ____________________________________________________________________________ _____ In terms of the content of Graze, the primary internal programming difference between Graze for Windows Version 3.0 and DOS Version 2.3 is that the Windows version allows for competition among plant species occupying the same paddock. In terms of execution, however, Graze for Windows incorporates all the commands necessary to develop input, execute the program and examine output within a single programming shell. Thus, the Graze for Windows version is much more "user friendly" that the DOS version. Future enhancements, including both the fundamental logic development and the input-output shell, will all be directed towards the Window's version. Summary ____________________________________________________________________________ _____ Although the release of the research model Graze for Windows to the general public is at no direct cost, this model represents a considerable investment by a number of universities and governmental agencies. We hope that it can be of benefit to all who wish to use it. The publications by Parsch and Loewer (1985) (User Guide) and Loewer and Parsch (1985) (Case Studies) provide considerable detail concerning the assumptions that are associated with using and interpreting the Graze model. Serious users of Graze would be well advised to examine these publications. The initial release of the Graze for Windows is designated Version 3.02 As with all new releases, we expect to find a number of "bugs." Likewise, we plan to incorporate a number of new features in later versions. Thus, some of the details presented previously will be altered in future versions. Certainly, we welcome all your comments as we attempt to make this a better program. Best regards, Otto J. Loewer