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If you prefer to use an older version of Rumen8 they are available on this page.

Rumen8 3.0

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Rumen8 runs on Windows 7, 8.1 and 10 computers and needs a minimum screen resolution of 1024 x 768. Other than that, if your computer can run Windows adequately it should run Rumen8.


Rumen8 v3.0 (22Mb)
User Guide (6 Mb)

Version History

What's new version January 2018
  • Fixed a bug that caused a volume milk price to overwrite the component fat price in some circumstances.

What's new version January 2018
  • Fixed a bug with the new maximum milk prices.

What's new version January 2018
  • Maximum milk price has been increased.
  • Bug in the Optimiser spreadsheet has been fixed.
  • Bug loading stored diets after feed library changes has been fixed. Thanks to Hink P. for reporting this.

What's new version November 2017
  • Fixed a bug that was preventing the cow breed loading correctly from a save file.

What's new version November 2017
  • Minor bug fix in Costs tab.

What's new version October 2017
  • Bug fix in the Save As function. Thanks to Gonzalo T. for reporting this.

What's new version October 2017
  • Added current diet DM% to dry and fresh weight tooltips in the main window.
  • Changed ingredients drop downs to show nothing, not "None" so can now jump straight to feeds starting with the letter N.
  • Added Clear current diet menu option.
  • Fixed bug preventing deletion of feeds with long names.
  • Feed and Mix list positions now remain the same after editing or deleting.
  • Fixed calculation of NFC% where diets with extremely high CP contents calculated negatives.
  • Fixed bug reloading save files with stored diets with negative DCAD and no performance indicators.
  • Fixed a bug in the calculation of $Milk/$Feed that reset MS/DMI in error.

What's new version August 2017
  • Rumen8 will correct some errors if they exist in the Preferences and Feed databases when started.
  • A status bar has been added to the bottom of the Splash screen.
  • When deleting feeds the user is now warned if it is used in mixes as they are deleted too.
  • Fixed a bug when feeds are created and immediately used in a mix.
  • Increased the number of ingredients in the unregistered version from 2 to 4.
  • Minor cosmetic changes to text.

What's new version June 2017
  • Bug fix where large quantities of low dry matter feed would not calculate the wet weight. Thanks to Angus D. for reporting this.

What's new version June 2017
  • Rumen8 now allows the Rumen8 folder to be located on a network drive without it being mapped to a drive letter.
  • The maximum cost for feeds and mixes has been increased to $99999/t DM. If you wish to use these expensive feeds you must delete your ~Rumen8\Libraries\Preferences.db file, start Rumen8 and allow it to copy an updated file (your preferences will be reset to the defaults).
  • Excess protein in the detail form now shows a dash not 0 when no diet is loaded.
  • Fixed a bug in the calculation of mix costs after losses in the ingredient tooltip.

What's new version June 2017
  • Linked the slider min and max values on the Animal tab to the values in the Preferences database. Thanks to Alastair G. for noticing the fat maximum was too low. It is recommended you delete your ~Rumen8\Libraries\Preferences.db file, start Rumen8 and allow it to copy an updated file (your preferences will be reset to the defaults).

What's new version May 2017
  • The 8 Queensland pastures in the feed library were incorrectly named perennials. They have been changed to annuals.

What's new version May 2017
  • Fixed a corruption in the feed library that was causing the feed editor to only show the first 62 feeds.

What's new version May 2017
  • Added keyboard shortcuts for the main menu options.
  • Changed the way the minerals calcium, phosphorus and magnesium supply and demand is presented.
  • Supply is now total mineral present in the diet. Previously is was total absorbable mineral present in the diet.
  • Demand is now total mineral required in the diet. Previously it was total absorbable mineral required in the diet.
  • Added a mineral detail window with a breakdown of demand into maintenance, lactation, growth and pregnancy. Also shows supply and absorption for the diet.
  • Detail windows can now be closed with the escape key and opened with a keyboard shortcut.
  • Updated Optimiser3.xlsm to version - bugfix for ADIN and added dry cow calculation for ME and MP for growth.
  • Maximise pellets added to the feed library.
  • The User Guide has been updated to include the minerals detail window.

What's new version April 2017
  • Fixed a bug in the calculation of mix NDF and eNDF. Thanks to Daniel E. for reporting this.
  • Fixed a bug in the calculation of mineral absorption in mixes.

What's new version March 2017
  • The number of diet ingredients has been increased from 10 to 15.
  • The window layout has been improved with important diet financial parameters always visible.
    • Feed mixes can be created and used in multiple diets as a single ingredient.
  • Animal demand and supply of the minerals calcium, phosphorous and magnesium has been included.
  • Diet DCAD is now calculated if ingredient DCAD is available.
  • The feed library has been updated and expanded to over 260 feeds.
  • Greatly expanded help and nutrition information is available via tooltips.
  • Four sets of recommended levels can be set for important diet parameters and then feedback is provided via traffic lights.
  • Notes about the current diet can be kept within Rumen8.
  • An expanded range of cost, margin and feed efficiency parameters allow better comparisons between diets.
  • ME and MP Detail windows can remain open allowing easier monitoring of supply and demand calculations.
  • The Fat: Protein ratio and energy corrected milk have been added to the Animal tab.
  • The Forage: Concentrate ratio is now calculated for the diet.
  • Concentration and proportion units can be changed to percent by the user in the Preferences.
  • Multiple feed libraries are now supported.
  • The Optimiser now works with Microsoft Excel 2010, 2013 and 2016.
  • Animal activity has been simplified.
  • The standard cows have been expanded to include 9000 and 10000 litre lactations.
  • Changing animal values has been made faster and easier with sliders instead of input boxes.
  • Days in milk and days pregnant can now be set on a calendar.
  • Diets being compared can now have a description.
  • The dry cow period has been split into early and springer mobs.
  • Energy, protein and ingredient details are now accessible from the menu.
  • Feed and mix details are available by hovering the mouse over the ingredient name.
  • The traffic lights are now suitable for most colour blind users.
  • The total diet weight is now displayed as fed and on a dry matter basis.
  • The Preferences can be reset to the default values.
  • Rumen8 is compatible with Windows 10.
  • Amino acids have been removed.
  • A saved diet file (.rm8) have been associated with Rumen8 so can be opened in Windows Explorer.
  • The User Guide and Training Manual for Rumen8 has been updated.
  • A Feed Companion has been written that provides a easy visual reference for feed values.

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Rumen8 2

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Minimum requirements

Rumen8 2 requires the Microsoft Windows operating system to run. This can be Windows XP, Vista, 7, 8 or 8.1. It is recommended you run Windows Update and install all the updates recommended by Microsoft before installing Rumen8.
If you computer can run Windows adequately, it will be sufficient for Rumen8.
Rumen8 requires the Microsoft NET Framework version 4 or higher to be installed. If your computer has been fully updated this will be installed automatically for Windows XP. For Windows Vista, 7 and 8 version 4.5 of the NET Framework will be installed automatically and this is backward compatible with version 4.
Rumen8 also requires the Microsoft PowerPacks10 software. If this is not installed on your computer it will be installed automatically during the installation of Rumen8 if your computer has an Internet connection. If your computer is offline the PowerPack10 software can be downloaded from the Rumen8 or Microsoft websites on another machine and then installed separately before installing Rumen8.


Rumen8 The installer for Rumen8 (4.5 MB)

Guide The User Guide (it is also in the installer 3.5 MB)

Report An independent evaluation of Rumen8 v1 (756 KB)

Framework Optional - .NET Framework support file from Microsoft (50.4 MB)

PowerPacks Optional - PowerPacks10 from Microsoft (447 KB)

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Please note

  1. Some users are reporting difficulty in downloading and installing Rumen8 with anti-virus software active. For example, Norton Anti-virus may incorrectly identify the Rumen8 installer as a threat and remove it without any feedback to the user. If you are having problems like this just turn off your anti-virus package while you download and install Rumen8. Don’t forget to turn it back on afterwards.
  2. For existing users of Rumen8 version 1, the feed library has a new location. It now lives in the \Rumen8\Libraries folder in your Documents folder.
  3. Rumen8 version 2 no longer creates a desktop shortcut. To start it for the first time you must go into the All Programs section of the Start Menu. Pin the Start Menu icon to the Desktop or Taskbar if you still prefer a Rumen8 icon there.
  4. Users in non English speaking countries may have problems loading the feed library if the default decimal symbol in your location is not a period. If this occurs you must change the decimal character back to a period (.) in the Control Panel, Region and Language, Formats, Additional Settings and then the Decimal symbol drop down menu. Please contact me if you require further information or assistance with this.

Version History

What's new in Version (May 2017)
  • Added feed amount to the warning message when an existing diet feed is no longer found in the visible feed library.
What's new in Version (September 2015)
  • Changes to the DUP calculation in the previous version were incorrect so it has been reverted to the original correct formula (the error was in the test data, not Rumen8).
What's new in Version (September 2015)
  • Fixed a bug in the calculation of DUP is the feed had ADIN information. This was resulting in a small under estimate of the MP supply from the diet.
What's new in Version (December 2015)
  • Added a menu option to reload the feed library from the disk. Useful if you run multiple instances of Rumen8 and have updated the feed library in one of them.
  • Updated the User Guide to the latest version.
  • Added the units (g) to the Excess protein tooltip in the MP Detail window.
  • Added an 'OR' to the excess protein penalties on the Diet Detail tab to make it clear the kg liveweight change and litres of milk forgone are not cumulative.
  • Added tooltips to the Amount and Wet column headings on the Diet Detail tab to better explain losses only apply to the costs, not the amount fed specified in the feed amounts.
  • Fixed a bug that resulted in the Intake traffic light not working when one of the feeds did not have an NDF value even when intake is estimated using the NRC methodology.
What’s new in Version (September 2015)
  • No changes, just modified the install package to stop it getting incorrectly listed as containing a virus.
What’s new in Version (March 2015)
  • Fixed a couple of annoying spelling errors. Thanks to Steve Little and Matthew Bekker for pointing them out.
  • Added entry of herd cow numbers to the Cow tab so margin can be calculated for the entire herd, not just one cow.
What’s new in Version (January 2015)
  • Fixed an incorrect milk price calculation when the milk payment prices were entered for components.
  • Changed the behaviour of the component cost lines on the Costs tab so they are now invisible when the diet component is set to ’None’ to improve the clarity of the screen.
What’s new in Version (November 2014)
  • The optimiser spreadsheets used by Rumen8 to optimise diets have been updated to reflect changes made in version 2.
  • The User Guide has been updated to remove the suggestion the optimiser function may work with Excel 2010 or 2013, it doesn’t.
What’s new in Version (September 2014)
  • Updated feed library to remove corrupted aN values for many of the feeds.
  • Rumen8 no longer displays diet performance under a maintenance level of feeding. This is because some of the protein relationships are not valid below maintenance feeding.
What’s new in Version (August 2014)
  • Compatibility with Windows Vista, 7, 8 and 8.1.
  • Library files such as the feed, cow and preferences are now kept under the user documents folder allowing easy access and backup.
  • Supports multiple users on one computer with independent feed libraries and preferences.
  • New Diet tab that presents only the 6 most important diet parameters to the user to allow easier diet balancing for new users.
  • New Prices tab that allows the user to modify component feed costs for the current diet without going into the feed editor.
  • New Costs tab that allows the user to enter 24 milk prices, 12 as cents per litre and 12 as a payment for fat + protein with a volume discount. Switching between milk prices only takes two clicks.
  • Online updating from within Rumen8.
  • Diets can be created for non-lactating mature cows.
  • Cosmetic updates to reflect the user interface on later versions of Windows.
  • The user interface has been de-cluttered to provide fewer distractions for new users.
  • The feed library editor now displays feed parameters as the user moves through them and can be enlarged to view more of large feed libraries.
  • Multiple feeds can be selected and unselected in the feed library editor.
  • Feed names must now be unique within a library.
  • Local feed libraries can be used in folders with saved diets so smaller feed libraries can be created that are farm specific.
  • Total excess protein is now calculated, not just excess ERDP.
  • The maximum number of feeds has been doubled to 2000.
  • Improved error and file handling so error messages, particularly with the library files, are more specific and easier to understand.
  • The Optimiser tab is hidden by default, as it is no longer a supported function.
  • Library files are checked on start and if they have been deleted or corrupted Rumen8 offers to re-copy the default libraries.
  • 5% safety margin now applies to protein, not just energy.
  • Added the calculation of NDF from forage as a percentage of live weight.
  • Bug fixed that may have resulted in incorrect ADIN calculation in some situations.
  • Bug fixed where reverting a feed to the pre editing parameters set aN to 0.
  • Bug fixed where ME requirement for growth was under estimated if the cow was losing weight.
  • The Cow tab now calculates milk solids from yield and components entered by the user.
  • User settings are now stored in the application settings file, not the registry.
  • Version 2 of Rumen8 requires a new registration code.
  • A new user guide for Rumen8 version 2.
  • A new home on the Internet at and support at

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Rumen8 1

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Please note the registration number for Rumen8 version 2 will not work with Rumen8 version 1.


Rumen8 The installer for Rumen8 version 1 (2.5 MB)

Manual The draft Rumen8 manual (588 KB)

Report An independent evaluation of Rumen8 (756 KB)

Framework Optional - .NET Framework support file from Microsoft (50.4 MB)

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Windows XP users

If you are still using the Microsoft Windows XP operating system Rumen8 requires Microsoft .Net Framework to be installed before its installation.  When you attempt to install Rumen8 you will be told if you do not have this installed.
It is available as a free download from the Microsoft site through the Windows Update program under optional downloads or from the Download Centre directly (link above).
If you are using Windows Vista, 7 or 8 the .Net framework is already included with the Windows operating system.

Before upgrading copy your library files

Rumen8 stores user preferences, cow and feed data in the system directory by default.

“\Program Files\Department of Agriculture and Food Western Australia\Rumen8”

Before upgrading copy the files prefs.csv, cow.csv and feed.csv to your documents directory so you have a backup in case installation overwrites your files. These files should be part of your normal backup program. Copy the files back after upgrading to the newer version of Rumen8 if required.

Minimum requirements

Rumen8 is available for Microsoft Windows based computers running XP and later. Any computer less than 8 years old will run it without any problems.

Windows 7 users

Some Windows 7 (64 bit version) users have reported problems saving preferences and editing the feed library. To solve this Rumen8 must be run as an administrator.
  1. Right click on the Rumen8 icon on the desktop and select “Properties”
  2. Click on the “Compatibility” tab
  3. Click on the check box next to “Run this program as Administrator”
  4. Click on the OK button to exit the properties window
Rumen8 should now run correctly under Windows 7.

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Version History

What’s new in Version (May 2014)
  • Fixed a bug that caused ME required for growth to be underestimated if the cow was losing weight.
  • Re-enabled the ability to click on the splash screen objects to close it.
  • Made the end of install text more explicit in stating the optimiser function only works with Excel versions 2002, 2003 and 2007.
  • Removed window resizing code that was resulting in windows opening at odd sizes on non-default screen sizes.

What’s new in Version (Apr 2014)
  • Fixed a bug that under rare circumstances may result in the feed parameter aN being set to 0 for all feeds when the user reverted to an old feed library as they exited the feed editor. To check if this has occurred to your feed library ensure the required aN parameter is greater than 0 in the feed editor or feed library file (feed.csv).

What’s new in Version (Apr 2014)
  • Fixed a bug that resulted in milk income being calculated incorrectly if milk units were set to kilograms.
  • Fixed ADIN calculation error where blank ADIN value caused the calculation of DUP to work on ADIN=-9999 instead of switching to a proportion of UDP.

What’s new in Version (Sep 2013)
  • Cosmetic changes to comply with the new Department of Agriculture and Food branding guidelines.

What’s new in Version 1.2.1 (Jan 2010)
  • Rumen8 can now use the solver functionality of Microsoft Excel from Office 1997 through to 2007.
  • Optimiser setup controls have been moved from the menus to the preferences and now include which version of Microsoft Office is installed.
  • Feed costs can exceed $999 per tonne.
  • The Open and Save As dialog now remember the last directory.
  • The milk yield input box doesn’t reverse the digits entered if no decimal point is present.

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