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Estimate livestock nitrogen, carbon and volatile-solids excretion.

Source: R/excretion.R
estimate_n_excretion.Rd

Converts realised feed intake (the output of redistribute_feed()) into excreted nitrogen, carbon and volatile solids per year x territory x sub_territory x livestock_category. All excretion methods share one canonical nitrogen intake, n_intake = sum(intake_dm_t * feed_n_content), so the methods are directly comparable.

Usage

estimate_n_excretion(intake, options = list())

Arguments

intake

A tibble of realised feed intake with at least year, territory, sub_territory, livestock_category, item_cbs_code, feed_quality and intake_dm_t (the redistribute_feed() result).

options

A named list of method options:

  • method: "intake_minus_retention" (default, n_intake * (1 - n_retention_frac)) or "intake_minus_product_n" (n_intake - product_n).

  • method_vs: "intake_digestibility" (default, intake_dm_t * (1 - digestibility) * (1 - ash)).

  • product_n: a tibble (year, territory, sub_territory, livestock_category, product_n) required by "intake_minus_product_n".

Value

A tibble with one row per year x territory x sub_territory x livestock_category and columns n_intake, n_excretion, c_excretion, vs_excretion, method_n_excretion and method_vs.

Examples

intake <- tibble::tribble(
  ~year, ~territory, ~sub_territory, ~livestock_category,
  ~item_cbs_code, ~feed_quality, ~intake_dm_t,
  2020L, "ES", NA, "Cattle_milk", 2513L, "high_quality", 100,
  2020L, "ES", NA, "Cattle_milk", NA, "grass", 500
)
estimate_n_excretion(intake)
#> # A tibble: 1 × 10
#>    year territory sub_territory livestock_category n_intake n_excretion
#>   <int> <chr>     <lgl>         <chr>                 <dbl>       <dbl>
#> 1  2020 ES        NA            Cattle_milk            11.9        9.49
#> # ℹ 4 more variables: c_excretion <dbl>, vs_excretion <dbl>,
#> #   method_n_excretion <chr>, method_vs <chr>