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Livestock demography
This submodel simulates livestock herd demography and slaughter effects. Initially part of the ROMFARMS model for animal husbandry on the Dutch Roman frontier, it focused on cattle, sheep, and horses. However, the code is adaptable for various animals, regions, and historical periods.
4
mentions
2
contributors
Description
This module was originally part of the ROMFARMS model (Joyce 2019) in order to simulate different scenarios of animal husbandry practice in the Dutch Roman frontier zone. The original module focused on understanding the economic viability of stockbreeding of cattle, sheep and horses for the Roman army. In particular slaughter rate proved to be an important parameter for this.
The standard input values used in the submodule are taken from the ROMFARMS source code, and are described and substantiated in Joyce (2019). However, users are free to adapt these values to their own research questions. The original module was developed for a runtime of 100 ticks (years), during which the herd size growth will be relatively modest using these parameters. However, after approx. 400 ticks the herd population will start to grow exponentially.
Inputs
| Name | Type | Description |
|---|---|---|
| species-type | string | animal species, OPTIONAL; for multiple species different rules can be specified if desired |
| alphaA | floating point | age of senescence of animal |
| alpha | floating point | standard deviation age of senescence |
| NMR | floating point | mortality rate of neonatal animals |
| BMR | floating point | background natural annual mortality rate of animals |
| FR | floating point | fertility rate of female animals |
| YAA | floating point | maximum age of young animal |
| AAA | floating point | minimum age of adult animal |
| YMR | floating point | mortality rate of young animal for slaughter |
| IMR | floating point | mortality rate of immature animal for slaughter |
| AMR | floating point | mortality rate of adult animal for slaughter |
| animals | turtle-set | animals found in livestock herd |
| sex (agent attribute) | string | sex of animal (F/M) |
| age (agent attribute) | integer | age of animal |
| fertility (agent attribute) | floating point | fertility of animal |
| lactating (agent attribute) | string | lactation state of animal (Y/N) |
| survivorship (agent attribute) | floating point | |
Outputs
| Name | Type | Description |
|---|---|---|
| pop-list | integer | number of animals |
| d-pop | integer | number of animals at end of year |
| d1-pop | integer | number of animals at start of year |
| livestock | turtle-set | current turtle set of animals |
| pop-growth | floating point | herd population growth as the percentage increase or decrease from the previous year |
Mentions
- 1.Author(s): Verhagen, P. and Kleijn, M. de and Joyce, J.Published in Heritage in 2021, page: 2081--2104
- 1.Author(s): Weijgertse, S.Published in 2020
- 2.Author(s): Joyce, J.A.Published in 2019
- 1.Author(s): Joyce, J. and Verhagen, P.Published in 2021
Contributors
JJ
Jamie Joyce
Author, Copyright Holder
PV
Philip Verhagen
Creator, Contributor, Copyright Holder, Thesis Advisor
Member of community
