Economic Feed Rate

Select the unique best contribution margin among caller measured feed/gain trials; not feed-cost-per-gain arithmetic, growth-curve extrapolation or feeding advice.

Description

Observed feeding trials can be compared by incremental biomass value minus feed cost.

Observed feeding trials can be compared by incremental biomass value minus feed cost. Selecting the best observed margin differs from fitting an economic response curve.^[1]

Select the unique best contribution margin among caller measured feed/gain trials; not feed-cost-per-gain arithmetic, growth-curve extrapolation or feeding advice.

When to use Economic Feed Rate

Use this tool to select the unique best contribution margin among caller measured feed/gain trials; not feed-cost-per-gain arithmetic, growth-curve extrapolation or feeding advice.

Prepare the cohort, water, feed or equipment measurements for one consistent operating period. Confirm nitrogen reporting bases, dry/wet masses, flow units and supplied design assumptions.

How to use Economic Feed Rate and understand its results

Prepare the cohort, water, feed or equipment measurements for one consistent operating period. Confirm nitrogen reporting bases, dry/wet masses, flow units and supplied design assumptions.
Enter trialFeedKgPerDay, trialGainKgPerDay, feedPricePerKg, fishValuePerKgGain using the field table and calculation rules, then run the tool.
Read trialContributionMarginsPerDay, bestObservedFeedKgPerDay, bestObservedMarginPerDay. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
trialFeedKgPerDay	Trial feed kg per day	list of number	Required
trialGainKgPerDay	Trial gain kg per day	list of number	Required
feedPricePerKg	Feed price per kg	number	Required
fishValuePerKgGain	Fish value per kg gain	number	Required

Enter aligned nonempty nonnegative feed and biomass-gain observations with nonnegative prices in a common currency. Calculate every margin and select the unique highest one. An exact tie for maximum is an input error; the best observed margin can still be negative.

Paired lists must be nonempty and have equal lengths.

trialMargin=biomassGainKg×fishValuePerKg−feedKg×feedPricePerKg

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
trialContributionMarginsPerDay	Trial contribution margins per day	list of number
bestObservedFeedKgPerDay	Best observed feed kg per day	number
bestObservedMarginPerDay	Best observed margin per day	number

json

{
  "input": {
    "trialFeedKgPerDay": [
      1,
      2,
      3
    ],
    "trialGainKgPerDay": [
      0.5,
      0.8,
      0.9
    ],
    "feedPricePerKg": 2,
    "fishValuePerKgGain": 10
  },
  "output": {
    "trialContributionMarginsPerDay": [
      3,
      4,
      3
    ],
    "bestObservedFeedKgPerDay": 2,
    "bestObservedMarginPerDay": 4
  }
}

Limitations and assumptions

The tool evaluates supplied trials without extrapolating or prescribing a feeding rate. Labor, time, mortality, fixed costs and risk are excluded.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Solids Production Rate: Partition supplied dry feed into uneaten and fecal solids then apply mechanical capture; dry-mass basis excludes dissolved organics and biological sludge. For a complementary task, use Grading Throughput: Plan batch grading duration with repeat passes, productive fraction and per-batch setup; reports unique fish throughput rather than counting repeated passes as new fish.

References

Economic Feed Rate — tool.io

Similar or alternative tools

Solids Production Rate
Partition supplied dry feed into uneaten and fecal solids then apply mechanical capture; dry-mass basis excludes dissolved organics and biological sludge.
Grading Throughput
Plan batch grading duration with repeat passes, productive fraction and per-batch setup; reports unique fish throughput rather than counting repeated passes as new fish.