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Redistribute available feed supply among livestock demand.

Source: R/redistribute_feed.R
redistribute_feed.Rd

Matches livestock feed demand to available feed items through a hierarchical allocation that follows the remaining-share principle to avoid exceeding availability. The redistribution path adapts to the fixed_demand column in the demand table.

Usage

redistribute_feed(feed_demand, feed_avail, options = list())

Arguments

feed_demand

A tibble of feed demand with columns year, territory, sub_territory, livestock_category, item_cbs_code, feed_group, feed_quality, demand_dm_t, and a logical fixed_demand.

feed_avail

A tibble of feed availability with columns year, sub_territory, item_cbs_code, feed_group, feed_quality, avail_dm_t, and feed_scale.

options

A named list of allocation options. See .redistribute_feed_options() for the available entries and their defaults. Supply grass_availability (a tibble with year, territory or area_code, and grass_avail_dm_t) to bound the otherwise-unlimited pasture grass at that supply per polity-year. The grass deficit then cascades: pasture grass is capped at the ceiling, the deficit is redistributed to leftover non-grass availability in the polity (added as 7_grass_deficit_substitute intake, limited by that leftover), and the residual stays as biologically-feasible underfeeding (scaling_factor < 1). Supply maintenance_share (a scalar fraction or a tibble with livestock_category and maintenance_share) to also diagnose polities pushed below maintenance; the over-stocked demand rows are attached to the result as the grass_deficit_diagnosis attribute. Set distribute_surplus = FALSE to suppress the surplus-distribution pass that pushes leftover CBS availability onto variable-demand livestock (correct for historical analyses where the CBS feed element is the realised consumption; keep TRUE, the default, for unconstrained scenario projections).

Value

A tibble of realised intake per demand row. When maintenance_share is supplied alongside grass_availability, a grass_deficit_diagnosis attribute lists demand rows underfed below maintenance.

Examples

# Two variable-demand categories in one territory competing for a single
# feed item. Availability (150) falls short of demand (200), so the
# remaining-share principle underfeeds both by the same factor rather than
# letting either exceed what is there.
feed_demand <- tibble::tribble(
  ~year, ~territory, ~sub_territory, ~livestock_category,
  ~item_cbs_code, ~feed_group, ~feed_quality, ~demand_dm_t, ~fixed_demand,
  2000L, "79", "79", "Cattle_milk",
  NA_integer_, NA_character_, "high_quality", 120, FALSE,
  2000L, "79", "79", "Pigs",
  NA_integer_, NA_character_, "high_quality", 80, FALSE
)

feed_avail <- tibble::tribble(
  ~year, ~territory, ~sub_territory, ~item_cbs_code, ~feed_group,
  ~feed_quality, ~avail_dm_t, ~feed_scale,
  2000L, "79", "79", 2514L, "cereals", "high_quality", 150, "national"
)

redistribute_feed(feed_demand, feed_avail)
#> # A tibble: 2 × 14
#>    year territory sub_territory livestock_category item_cbs_code feed_group
#>   <int> <chr>     <chr>         <chr>                      <int> <chr>     
#> 1  2000 79        79            Cattle_milk                 2514 cereals   
#> 2  2000 79        79            Pigs                        2514 cereals   
#> # ℹ 8 more variables: feed_quality <chr>, demand_dm_t <dbl>, intake_dm_t <dbl>,
#> #   scaling_factor <dbl>, hierarchy_level <chr>, requested_item <int>,
#> #   source_compartment <chr>, fixed_demand <lgl>