Dairies vary widely in the amount of feed they grow on-site versus purchase, which can also vary by year. Approximately 60% of dairy feed is sourced off-farm. Given that variability, FARM ES focuses on the dairy operation itself while using feed emissions factors for feed production. The feed emissions factors take into account USDA data on typical production practices by region. Using feed emissions factors allows FARM ES to provide a holistic, cradle-to-farmgate footprint – whether feed is sourced on-site or off-site. Version 3 of FARM ES, coming in 2024, will offer dairy farms the option to enter information about their unique cropping practices. It will still use feed emissions factors for any feed sourced off-site or for farms that choose not to enter the additional data.
Various forms of cropping methods are all accounted for in the “Feed Emissions” bucket.
The “Feed Production” emissions category uses emissions factors developed following LCA methods (described in this paper). The emissions factors take into account USDA data on typical production practices by region. The amount of each ration ingredient is multiplied by the applicable emissions factor to generate the emissions footprint.
Essentially, the model makes assumption about cropping practices in each region. It does not ask about the producer’s unique practices.
The data is collected for informational purposes only at this point. It does not impact the results. The data will be used to inform future model developments.
Evaluators are encouraged to select feed ingredient proxies when appropriate. The following table summarizes recommendations based on questions received to-date:
Feed Ingredient FARM ES Proxy
Earlage Corn silage
High-moisture corn Corn Grain
Rye hay Grass hay
Rye silage Grass silage
Snaplage Corn silage
Sorghum Sudan Other
Soybean hulls Other
The model makes assumptions about the rations for the other animal classes based on the findings from the LCA research. The GHG / energy footprint results include the impacts of feed from all classes (lactating, dry, heifer, etc.).
There are many farms that need to use the ‘all other feed’ category quite heavily. It can be difficult to know the ingredient breakdown for protein mixes. One could consider checking whether the farm can get an ingredient breakdown for the protein mix. That would make the results of FARM ES much more accurate.
If it’s not possible to find out the ingredient breakdown, then enter the data as given into FARM ES. There is a question that will pop up in the evaluation “To help FARM ES improve, please provide a little information about what is included in the ‘All Other Feed’ category for the farm’s lactating cow ration:”. Enter that it is a complete protein mix. The response will go into an anonymized dataset for researchers to inform improvement over time.
Even if you know the primary ingredient of the protein mix, it would be difficult to know what percentage of the protein mix the primary ingredient accounts for. That may not be entirely accurate, so it would be best to include the entire protein mix as “All Other Feed” until you can find out more about the mix itself.
The “Feed Emissions” category uses emissions factors developed following LCA methods (described in this paper). The emissions factors take into account USDA data on typical production practices by region. The amount of each ration ingredient is multiplied by the applicable emissions factor to generate the emissions footprint.
Most byproduct feed ingredients are not separately accounted for in FARM ES. They should be categorized under “all other feed”. The 11 primary feed types included in FARM ES made up 82% of the feed emissions in the original LCA research – so that’s why the model focuses efforts there. The supplementary material in these two papers gives more info about the assumed rations by region in the LCA research (https://www.sciencedirect.com/science/article/pii/S0958694612001999#appsec1 and https://www.sciencedirect.com/science/article/pii/S0958694612002051#appsec1)
Work is underway to include certain byproduct feeds in Version 3 of FARM ES.