Enter the purchased heifers into the field ‘Annual Avg Number of Heifers (2 months to first calf) raised OFF farm’. For the purchased dry cows, we would recommend including them in the ’Annual Avg Herd Size (Lactating and Dry)’. For example, if there are 1,000 head, and they purchase maybe 20 extra dry cows, put the total average herd size as 1,020.
If the facilities are close together geographically, you can do one evaluation for the farm as a whole and enter the information into one of the facility accounts. For the ‘percent’ dry field, enter it assuming the dry cows do not leave the facility.
FARM ES is LCA-based, so it’s trying to get the GHGs associated with the milk. Even though the dry cows leave that facility, the environmental impact associated with caring for the dry cows (feed, etc.) should be ‘associated’ with the milk from the facility that is doing the milking.
The difference between 0-2 months and older than 2 months would be in the ration amount and breakdown assumptions.
The reason FARM ES distinguishes the difference between animals raised off-farm is within the manure emissions section of the evaluation. FARM ES asks about the farm’s manure management, but for animals raised off-site there is no user information on the type of manure management – so the model uses assumptions about regional manure management strategies based on the LCA research findings.
Enter all calves as raised “off-farm” for 0-2 months, then enter that they are all raised as “on-farm” for 2 months and up. FARM ES distinguishes between on-farm and off-farm for the purpose of calculating manure emissions – it uses farm-specific information about the manure management systems for any animals raised on-site; and average, non-user-specific information about manure management systems for animal raised off-site.