Easy Dairy Cow Diets


Rumen8 can be downloaded and used straight away in trial mode but is restricted to 4 diet ingredients until it is registered. Registration is free.

To apply for a registration number please use the Contact page to send us a message with your name (first and last) and the email you would like to be contacted on. If you don't mind telling us where you are (country and region will do) and your role in the dairy industry it helps us see who is using Rumen8 and better target improvements in the future. Rumen8 emails are very infrequent and your email address will not be shared with any third parties.


Rumen8 runs on Windows 7, 8.1 and 10 computers with a minimum screen resolution of 1024 x 768 and .NET runtime version 4 installed. Other than that, if your computer can run Windows adequately it should run Rumen8.

Download the installer

To install Rumen8 you must agree to the license agreement. You can read it here and it will be displayed as part of the install process.

Stacks Image 60
Download the Windows installer for Rumen8 (52 MB).
If your virus scanner will not let you download an executable file (.EXE) download the installer in a zip file from here (password is 'password', all lower case).

Stacks Image 94
The SAP Crystal Reports Runtime is required to create reports - 32bit and 64bit (97 MB). These can also be downloaded from the SAP website.

Stacks Image 62
Download the Rumen8 User Guide (7 MB - included in the Rumen8 installer).

Stacks Image 64
Download the Rumen8 Training Manual (3 MB - included in the Rumen8 installer).

Stacks Image 66
Download the Rumen8 Feed Companion (2 MB - included in the Rumen8 installer).

If you are having trouble downloading and installing Rumen8, download the User Guide above which includes step by step instructions with screen shots to help you.
If the Windows 'SmartScreen' is preventing you running the installer look in the FAQ for instructions.

Stacks Image 138

Tropical Feed Library

If you are based in East Africa, SNV Kenya has developed a Rumen8 feed library for the region. It can be downloaded from them here.

Change log

Version December 2020

  • NEW
  • The Kingdom of the Netherlands logo has been added to the Acknowledgements page.
  • The Acknowledgements, References and EULA windows can be closed by pressing the escape key.

  • The optimiser setup instructions in the User Guide have been updated and improved to make the process clearer.

  • The calculation of net energy for milk production was slightly underestimating the ME demand.
  • Windows should no longer open off the top of the screen.
  • Preferences no longer fails on start for some users when a custom currency is selected.

Version September 2020

  • NEW
  • Feed and mix comments can now be edited in a larger window in the feed editor.
  • Feed and mix comments can be viewed in a larger window in the component detail window. URLs are blue and when clicked open in the default browser.
  • Feed and mixes in the feed editor lists can be double clicked on to edit.

  • The optimiser setup instructions in the User Guide have been updated and improved to make the process clearer.

  • Preferences cow NDF intake percent now correctly saves to 1 decimal place.
  • Preferences heifer NDF intake percent now saves.
  • The milk prices check when opening a diet file no longer offers to switch to another price when in Compact mode.

Version August 2020

  • NEW
  • The Optimiser tab now has diet parameters next to constraint ranges that highlight red when they are out of range and active.
  • The Optimiser tab has a new button allowing the user to choose from the recommended level ranges for common optimiser parameters.
  • You can now create a mix from the current diet from the Edit menu.
  • Standard cow definitions can now be modified in the preferences.
  • Recommended levels automatic switching can now be based on days pregnant in addition to day of lactation.
  • A feeds and mixes report is available from the feed editor.
  • Word search and jump to page has been added to the report preview.
  • MilkPrices.db3 and Preferences.db3 library files can now be located in any folder. Controls for new and opening existing library files are in preferences and the Milk prices tab.
  • If the current MilkPrices.db3 or Preferences.db3 library files are missing they can be replaced or located during start up.
  • File menu 'Open with libraries' and 'Save as with libraries' have been added allowing a folder to contain all library files and a rm8 file and be opened and saved with one click.
  • Reports are now able to be exported in multiple formats.

  • Standard cows no longer update the farm terrain or distance walked animal parameters.
  • The recommended levels selection buttons on the Diet detail tab now have tool tips that show the current ranges for day of lactation and days pregnant ranges when active.
  • Menu text is now capitalised correctly.
  • The preferences tool tip detail setting no longer has the option for none. Tool tips contain too much information to be turned off completely.
  • The extended tool tips now stay open longer.
  • The standard cow default parameters have been updated.
  • Feed efficiency $ Milk / $ Feed now has 3 decimal places.
  • Feed cost $/ME MJ and feed efficiency $ Milk/ $ Feed still display one decimal place even when the ‘Display cents’ preference is turned off.

  • The import feed file was not being closed correctly if it was opened and then the import cancelled by the user.
  • The day of lactation calculator on the Animal tab now allows 500-day lactations.

Version May 2020

  • Fixed
  • The tool tips on the main window have been restored.
  • Some tool tips have been reworded for clarity.

Version February 2020

  • NEW
  • Mineral demand for dry and transition/close-up cows is now based on Lean and Degaris Transition Cow Management (2010).
  • Supply and demand of minerals is now expressed as percent or g/kg of dry matter intake in the value tool tip.
  • A DCAD calculator is now available in the feed editor.
  • The term close-up is used instead of transition outside of Australia and New Zealand.

  • The icons for the 3 calculator buttons on the Animal tab have been changed.
  • The transition period has been lengthened from 21 to 28 days in line with Lean and Degaris Transition Cow Management (2010).
  • The dry matter intake estimate now shows a green traffic light or progress bar asymmetrically, so it is green earlier when the cow is not fully fed.
  • The feed editor's 'Add New' feed button has been removed to encourage users to only modify a copy of an existing feed. Hold the shift key down to access the 'Add New' functionality.
  • Selecting a standard cow no longer changes the DMI method or the number of cows in the herd.
  • The general preferences standard tool tips level tool tip made clearer.
  • The DMI 'standard' method renamed to 'conventional' on Animal tab and general preferences.
  • Optimiser spreadsheet logo updated and some cosmetic changes.

  • When adding a new feed all the required radio buttons show red as not set, not just management category.
  • The feed editor feeds Add Copy button tool tip fixed.
  • The tab order on the feed editor feed parameters now works correctly.
  • A few spelling errors fixed.

Version November 2019

  • NEW
  • Milk price volume discount can now be negative allowing a volume payment.
  • NDF from forage, eNDF, starch, sugar, NFC, F:C, ash and fat now report total quantity of kilograms dry matter in the tool tip of the percentage value.
  • If a read only shared feed library cannot be upgraded it now reports the library author when informing the user.

  • References to milk solids or MS changed to fat+protein or FP outside of Australia and New Zealand for clarity.
  • Minimum starch recommended level reduced to 0 from 10%.
  • Default cow modified to be more representative of a mid-lactation animal. Days pregnant is now 70 and days in milk 150.
  • Some tool tips improved for clarity.
  • Units added to feed efficiency recommended levels so clearer.

  • Bug introduced in previous update that prevented recommended levels day of lactation parameter saving fixed.
  • Definition of eNDF abbreviation in the user guide and help corrected.

Version October 2019

  • NEW
  • Added ‘Compact’ mode that restores the simplicity of Rumen8 version 2.
  • The feed editor menu option now has a keyboard shortcut Control-F.
  • The optimiser has an additional fourth ingredient amount fed constraint.
  • The optimiser now allows any ingredient amount fed to be constrained.
  • The feed editor can now import a CSV file with all the diet parameters.
  • Mix feed percentages can now be entered on an ‘as fed’ basis.

  • Margin over feed costs (MOFC) has been renamed Margin above feed costs (MAFC) on the Diet report for countries other than Australia and New Zealand.
  • Rumen8 version 2 diet save files are now opened via the File Open menu option and the File Import menu choice has been removed.
  • The optimiser ingredient amount fed constraints are set with entry boxes, not a slider.
  • The Optimiser ‘kilograms of concentrate’ constraint has been reduced to 1 decimal place.
  • The End User License Agreement (EULA) has changed and must be accepted to use Rumen8.
  • Cosmetic changes for the Splash and About windows.
  • Added an Acknowledgements window available from the About window.

  • A Forage:Concentrate ratio of 0:100 now correctly causes a warning on the Diet tab.
  • Particle size class and protein type are now correctly reported in the diet ingredient tool tip.

Version July 2019

  • Rumen8 will now open with an empty feed library.

  • Mixes with missing feeds no longer prevent Rumen8 from starting. You will be warning and asked to fix or delete the mix in the feed editor.
  • Mixes with feeds with a missing cost no longer prevent Rumen8 from starting.
  • Fixed the feed editor so a feed name warning was not incorrectly carried over to the next feed in rare circumstances.

Version July 2019

  • NEW
  • A second feed library can be used alongside the usual default or user feed library. This library is intended for teams and cannot be edited.
  • A warning appears on the Optimiser tab if any of the diet ingredients have no cost.

  • Open and save folder paths are now remembered between sessions.
  • Feed library file names have been added to the User Feed Library flag on the main window.
  • The optimiser constraints for concentrate and ingredient 1, 2 and 3 can now be set to 2 decimal places.
  • Better warning messages when a diet ingredient is missing from the feed library.
  • A flag appears on the main window showing when a currency divisor has been set in the Preferences.
  • The feed editor select tab layout has been improved.

  • Changing the name of an existing feed now updates any parent mixes correctly.
  • The prompt window now displays the correct store number when restoring a diet.

Version May 2019

  • Fixed a bug that allowed entry of a milk price just over the maximum 999/L.
  • Fixed a bug that increased milk prices in the save file.

Version May 2019

  • Fixed a bug that prevented dry matter content being calculated for some mixes due to a rounding error.

Version May 2019

  • Fixed a bug that incorrectly calculated the mix dry matter cost if the cost on an ‘as fed’ basis was entered.
  • Fixed a bug that allowed a new mix to be saved with no name.

Version April 2019

  • Protein demand by the cow is now calculated using the ‘Feed into Milk’ standard. Rumen8 will change to this method automatically when it starts for the first time. Using the previous AFRC method is not recommended but can be selected in the Advanced Preferences.

  • NEW
  • The cow protein demand model has been updated to the ‘Feed into Milk’ standard.
  • The currency now defaults to the system symbol and can be changed in the Preferences.
  • Currency cents can be turned off in the Preferences.
  • Diet ingredients can be dragged from the ingredient number and dropped on another ingredient number or name to swap the position of the two ingredients.
  • When importing feeds and mixes you can now choose to use feeds already in the feed library if they have the same parameters (other than the name).
  • Multiple feeds and mixes can be deleted at once in the feed editor.
  • The cost of feed ingredients is displayed in the mix editor.
  • Enteric methane production has been added to the diet copy/paste function.

  • Improved sort buttons layout in the feed editor.
  • Feed lists update more quickly in the feed editor.
  • Import and export feeds now prevents you from exporting to or importing from the current feed library.

  • Silage ‘Feed protein type’ may be incorrectly classed as ‘Grass silage’ instead of ‘Other silage’ when editing.
    Note: Rumen8 will correct all the provided non-grass silages on start-up. User created feeds will also be corrected if their name is the same as the Rumen8 provided feed with the addition of a suffix.
    Please check all silages to ensure feed protein type is correct.
  • The methane intensity units now change correctly based on milk units.
  • Feed import settings and folder paths are now remembered between sessions.
  • Bug fixed that allowed feed or mix edit after import without feed or mix selected.

Version February 2019

  • NEW
  • Enteric methane intensity and total production equations have been added to the diet detail tab.
  • Diet ingredients weight as fed is now appended to data copied to the clipboard by the Edit->Copy menus allowing it to be pasted into other applications.
  • Total fat in the diet is now reported in the fat % tool tip on the Diet detail tab.

Version February 2019

  • NEW
  • Active recommended levels are now shown in the tool tips for the small traffic lights on the Animal tab and the constraint range text on the Optimiser tab.

  • Optimiser update message links to the correct section of the User Guide.
  • Optimiser updater improved.
  • Missing feed library file message now exits correctly if the user chooses no new file.
  • Diet comparison reports can now be saved to PDF files.
  • Diet comparison reports no longer display 0’s for empty compare diets.
  • Numerous minor cosmetic improvements.

Version January 2019

  • NEW
  • NDF intake potential can be set individually for cows, dries, transition cows and heifers in the Preferences.
  • Standard intake potential now has user preferences for dry and transition cows.
  • Dry matter intake for NDF on the Diet Detail tab now shows the target quantity in the tool tip.
  • Recommended levels sets in the Preferences can now be linked to a cow days in milk range and will change sets automatically. Switching between automatic and manual selection of recommended levels can be done on the Diet Detail tab via a new A/M button.
  • When opening a saved diet you will be warned if the intake potential parameters have changed since the diet was saved. This is on by default in the Preferences.
  • When opening a saved diet you can be warned if the milk price has changed since the diet was saved. This is off by default in the Preferences.
  • The Split Herd tab can now be hidden in the Preferences if you don’t have split calving herds.
  • DCAD has been added to the diet report.
  • The start up window now shows a progress bar while Rumen8 loads.
  • The Diet tab progress bars and percentage values now show actual values in the tool tip.

  • Intake potential estimation methods renamed to Standard and NDF.
  • Intake potential method is now a property of the cow and set on the Animal tab, not a preference setting applied to all animals.
  • The NDF recommended level maximum has been increased from 50 to 70%
  • The Advanced Preferences value for net weight gain energy requirement has been changed from 19 to 22 MJ/kg liveweight gain if the values for net weight gain and loss are still the defaults. This is the result of updated literature search.
  • Forage:Concentrate ratio now reports 0:100 or 100:0 instead of – if the diet is all one type.
  • Milk price components ‘Volume’ discount has been renamed ‘Discount’ and units change with the milk units preference.
  • The optimiser parameter sliders have been widened to make them easier to set accurately.
  • Total solids ratio renamed to Fat to Protein ratio to be clearer for international users.

  • The Organic matter tool tip now correctly shows – when no diet is loaded.
  • The Diet tab now returns to the correct location if it is hidden and then turned back on.
  • Recommended levels for NDF from forage as a percentage of liveweight now save correctly.
  • A bug in the MilkPrice.db3 upgrade routine that caused an occasional failure during the upgrade has been fixed.
  • Feed costs in the Diet detail window now display correctly when greater than $9999.
  • Feed as a percent of income now displays percentages greater than 100.

Version December 2018

  • Fixed bug that displayed the equivalent milk prices incorrectly for dry cows.
  • Fixed a bug that reset the heifer weight to 40kg occasionally.

Version November 2018

  • Fixed a bug that prevented Rumen8 from prompting to save when quitting with unsaved changes.

Version November 2018

  • NEW
  • New diet comparison report added.
  • Warnings added to the diet ingredients if the maximum feeding rate is exceeded.
  • A fifth set of recommended levels added along with an off option. Now allows parameter ranges for early, mid & late lactation plus dry and transition herds.
  • Maximum milk price increased to $9999.99.
  • Diet ash content/organic matter content tool tip added to the Diet Detail tab.

  • Milk price now changes to cents per kilogram when the milk units are kilograms.
  • Cow live weight change body condition score calculator revised and includes Penn State 1-5 system.
  • Penn State body condition score system added to the live weight change tool tip.

  • Fixed a bug that prevented some diet costs saving.

Version August 2018

  • Feed costs are no longer displayed if any diet ingredient is missing its cost.

  • Fixed a bug in the calculation of the $Milk/$Feed efficiency parameter.

Version June 2018

  • NEW
  • Heifer mineral requirement added.
  • Standard cows with 2000, 3000 & 4000 litre lactations added.
  • Restoring a stored diet now has the option to also restore the animal.
  • Maximum feed cost has been increased to $9999999/tonne.
  • The herd margin will now display negative margins.
  • Shift clicking a diet ingredient number will remove that ingredient.
  • Provided grams of MP/litre of milk table in the tooltip for true protein concentration on the Animal tab.
  • Added MP efficiency coefficients to the MP Detail window.

  • Feed editor import cancel button changed to Skip All to make the function clearer.
  • Added tool tips to the Feed editor import CSV buttons.
  • Changed the Import, Diet menu text to make it’s function clearer.
  • Pasted forage:concentrate ratio increased to 2 decimal places and the title is clearer.
  • The report disclaimer entry box style now matches others.
  • Calculated ingredient amount (wet from entered dry matter and vice versa) now rounded to 2 decimal places to prevent rounding inconsistencies.
  • Expanded the explanation for excess protein removal cost tooltip and changed units to KJ/g N.
  • Expanded the excess protein forgone milk explanation in the tool tip.
  • Improved wording of save default animal dialog box.
  • Improved wording in the User Feed Library flag tooltip.
  • Improved wording for menu option to move dry cow into transition herd.

  • Fixed a bug that prevented the eNDF recommended levels traffic light from working.
  • Fixed a bug that prevented the Forage:Concentrate recommended levels traffic light from turning off when no diet was loaded.
  • Fixed a bug that prevented the recommended DCAD levels being updated to the 2017 values.
  • Fixed a bug that prevented restoring the Split Herd diet in some circumstances.
  • Fixed a bug that blanked wet cost when dry matter cost was entered as 0 and vice versa in feed and mix editor.
  • Fixed calculation of the non-entered cost when the dry matter of the mix is changed and the mix is complete.
  • Numerous internal updates to allow easier maintenance and future updates.

Version May 2018

  • NEW
  • Added the NDF intake as a percent of liveweight to the Max DMI NDF% value on the Diet Detail tab.

  • Improved the heifer protein demand calculation by replacing the default 1.25 adjustment with a correction factor based on liveweight (Tedeschi 2015). This will increase heifer protein demand.
  • Expanded tooltip information in Preferences for MP requirement adjustment and NDF intake as a percent of liveweight.

Version April 2018

  • Fixed a bug that prevented ingredient 10 restoring correctly from the Compare tab.
  • Fixed a calculation error on the Diet report for ingredient mineral supply. Thanks to David H. for reporting this.
  • Fixed the calculation of mix mineral absorption rates.

Version March 2018

  • NEW
  • Added dry matter intake as a percentage of cow liveweight to the Diet detail tab.
  • Added tool tips to the Milk price tab headings.

  • The Diet report now allows negative margin over feed costs and larger dollar values.
  • The minimise and maximise controls have been restored to the main windows.

  • Fixed a mix cost bug that prevented fresh weight costs being entered. Thanks to Glenys H. for reporting this.
  • Fixed bug where preference validation values were not being read from the file correctly.

Version March 2018

  • Fixed occasional bug when importing an old diet file after a failed attempt to import a non-Rumen8 csv file.
  • Improved milk prices database upgrade process.

Version March 2018

  • NEW
  • Additional information about the Metabolisable Protein Correction Factor added to the User Guide, Help and Advanced preferences tooltip.

  • Fixed a bug when importing a v2 feed library.
  • Fixed bug when exporting mixes.

Version March 2018

  • NEW
  • Diet, Batch and Feeding reports can be printed or saved as PDFs from the File menu (reports require the SAP runtime software to be installed, see Getting Started in the User Guide for details).
  • Easily share feeds and mixes by exporting and importing them from the Feed Editor Selection tab.
  • Combine separate diets for split herds in the new Split herd tab.
  • Define up to 10 milk price sets in the Milk Price tab.
  • Create diets for heifers by selecting a heifer in the Breed & Maturity drop-down menu.
  • Calculate the target growth rate for heifer herds with the calculator on the Animal tab.
  • Suggest cow live weight change with the calculator on the Animal tab.
  • Estimate the additional liveweight change required to increase body condition score in the cow live weight change calculator.
  • Milk fever risk is estimated for transition cow diets on the Diet Detail tab.
  • There is now a warning on the Diet tab if a monitored parameter on the Diet Detail tab is out of the recommended range.

  • Animal parameters can be entered directly on the Animal tab in addition to using the sliders.
  • The updated User Guide is now available from the Help menu, the F1 key or the help button (?) in the window title bar.

Privacy Policy of Rumen8 Nutrition Pty Ltd
This website collects some Personal Data from its Users.

Personal Data collected for the following purposes and using the following services:

Google Analytics
Personal Data: Cookies; Usage Data

Contacting the User
Contact/Registration form
Personal Data: country; email address; field of activity; first name; last name

Mailing list of registered users
Personal Data: email address; first name; last name

Contact information
Owner and Data Controller
Rumen8 Nutrition Pty Ltd
Bunbury WA 6230

Owner contact email: