How is a ration created in RuFaS?
Regardless of whether or not a user chooses to provide their own ration or have RuFaS build and feed a ration optimized for least-cost, RuFaS needs a set of ingredients to work from. The RuFaS feed library should be consulted for the full list of ingredients and ingredients that are in both the NASEM and NRC libraries can be used. Users interested in feeding a ration that they define, need to provide a list of ingredients and their relative % dry matter intake for each animal class (pre-weaned calves, growing heifers, close-up animals, and lactating cows). Note that, for the time being, only one set of feeds and ration formula can be provided for each animal class.
If a user would like RuFaS to use the list of ingredients to formulate a least-cost ration, it is imperative that proper costs are inputted for each ingredient listed, but the % dry matter intake in the user defined ration percentages does not need to be included. Feed costs need to be entered in $ / kg DM. RuFaS will then use all the ingredients available (based on costs and inventory available if the feed is homegrown) to create a ration that meets the nutritional requirements of the animal class and is cost-optimized.
How do inputted rations and ingredients impact milk production?
The user can determine how closely RuFaS follows the inputted ration and matches milk production to annual milk production. If the user defined ration is set to “true”, two additional inputs (“milk reduction maximum” and “tolerance”) become important. Milk reduction maximum will control how much RuFaS is allowed to decrease the milk production using the defined ration in order to meet the nutrient requirements of the animals. Tolerance is the percentage by which RuFaS can alter the percentage dry matter of an individual ingredient in order to adjust the ration to meet the nutrient requirements of the cows with a given milk production. RuFaS completes an iterative process of checking requirements against the formulated ration to create the ration that best fits all parameters given by the user.
What are the inputs for feeding animals in RuFaS?
Feed ingredients and % dry matter (as applicable) for each animal class (pre-weaned calves, growing heifers, close-up, and lactating cows):
Forages
Concentrates
Minerals
Feed cost
Milk reduction maximum and tolerance
What outputs should one expect from feeding animals in RuFaS?
While the total list of module outputs can be accessed through use of the model, a few key outputs of interest include:
Production outputs:
Dry matter intake by feed ingredient
Total dry matter intake by animal class
Environmental outputs (available by animal class):
Feed emissions, assuming the feeds are purchased, not homegrown
What is the future of the feed storage module?
Alternative ration optimizations: Today RuFaS has a lowest-cost optimization for ration formulation if user defined rations are not desired. Future ration optimizations include those optimized for highest milk production or optimized for lowest environmental footprint.
Multiple rations per animal class: The limitation of one ration per animal class prevents the user from modeling, for example, a farm that has a high-cow and low-cow ration for lactating cows. We plan to expand the options for designating multiple feed lists and rations within each animal class in the near future.