Herd dynamics & inventory updates

[jadamchick]

Updated 9 Sept 2026

Work divided into 2 sub-groups:

1. Improve core logic of herd dynamics -- updating the connectivity between sub-populations of the animal herd while maintaining/improving the ability for users to simulate a stable herd with defined composition

• Update culling logic from "pull" to "push" -- sub-issue 1684, PR [Animal] Maintaining herd size #2622

• Create option to customize ranking & eligibility of cows to sell - sub-issue 3109, PR [Animal] Make oversupply cull eligibility and ranking criteria user inputs #3120

• Create input for youngstock mortality for calves and heifers - sub-issue 2989, PR [Animal] Implement heifer and calf cull rate as an user input #3003

• Create option to input female_calf_num as direct user input - sub-issue 2783, PR [Animal]Add count-based female calf retention option (Option 2) #3078

• Create parity-adjusted and/or component-adjusted milk production metrics to use for ranking cows for culling or breeding -- sub issue 2012, PR [Animal] M305 lactation curve implementation #2715

• Improve culling inputs for clarity and inputs able to be known by the user -- sub issue 2694, PR [Animal] Streamline Animal Culling Inputs #3241

• Create useful & streamlined herd demographic, sold cow, and milk outputs -- sub issue 3210, PR Add high priority heard outputs #3287

• documentation for all of the above tasks: scientific documentation, gray literature

• testing: characterize time to herd stability (issue 2962)

• testing: demonstrate that herd management "interventions" have expected impact (improved repro, decreased mortality?)

2. Expand herd management scenarios -- Enable customized semen strategies with calf outcomes and downstream impacts

• Draft potential design - sub-issue 2779

• Coordinate with Yijing's planned updates -- in discussion 4/29, decide to focus on PR#2966 first and then will do this following

• Finalize scope and design doc -- link included in issue Expand options for flexible customized semen allocation strategies #2779

• Coordinate mapping with econ layer

• documentation: scientific documentation, gray literature

• evaluation farms: update input fields and values

Future work will be outlined in issue #3105

Timeline to work progress in google sheet here: https://docs.google.com/spreadsheets/d/1yOhua8evWlIRntXNrNwXBShgrJo7RWpb9Vh854Z02gg/edit?usp=sharing