What is the feed conversion ratio formula?

FCR = Total feed consumed (kg dry matter) / Liveweight gain (kg). Lower FCR = better efficiency. Broiler chickens: FCR ≈1.6–1.9. Pigs: 2.5–3.0. Beef cattle: 6–8. Fish: 1.0–1.5.

What is residual feed intake (RFI)?

RFI = Actual intake − Expected intake based on growth rate and body size. Negative RFI = more efficient than expected. RFI selection reduces methane emissions by 10–20% in cattle.

Feed Conversion Ratio (FCR) Calculator

Constant	Symbol	Value	Units
Speed of light	c	2.99792458×10⁸	m/s
Planck's constant	h	6.62607015×10⁻³‴	J·s
Boltzmann constant	kʙ	1.380649×10⁻²³	J/K
Avogadro's number	Nₐ	6.02214076×10²³	mol⁻¹
Gravitational constant	G	6.6743×10⁻¹¹	N·m²/kg²
Gas constant	R	8.31446	J/(mol·K)
Elementary charge	e	1.602176634×10⁻¹⁹	C
Electron mass	mₑ	9.1093837015×10⁻³¹	kg
Proton mass	mₚ	1.67262192369×10⁻²⁷	kg
Fine-structure constant	α	7.2973525693×10⁻³	dimensionless

Constant

Symbol

Value

Speed of light

2.99792458×10⁸

Planck's constant

6.62607015×10⁻³‴

Boltzmann constant

kʙ

1.380649×10⁻²³

Avogadro's number

Nₐ

6.02214076×10²³

Gravitational constant

6.6743×10⁻¹¹

Gas constant

8.31446

Elementary charge

1.602176634×10⁻¹⁹

Electron mass

mₑ

9.1093837015×10⁻³¹

Proton mass

mₚ

1.67262192369×10⁻²⁷

Fine-structure constant

7.2973525693×10⁻³

Formula Definitions

The Feed Conversion Ratio (FCR) Calculator works by applying a well-defined formula to the values you enter. Understanding the formula behind the calculation helps you interpret the result and check that your inputs are correct. Below we break down the key components that drive the Feed Conversion.

The core formula used by this calculator is:

Result = f(physical quantities, constants, conditions)

Each variable in the formula has a specific meaning:

physical quantities — Measured values with units entered into the Feed Conversion.
constants — Physical or chemical constants (e.g. CODATA values, gas constant, Avogadro's number).
conditions — Temperature, pressure, concentration, or environmental state of the system.
Result — Computed physical or chemical quantity with associated units.

Note: Compare results with standard reference values or published experimental data.

How to Use This Calculator

Enter the required values. Enter the required values into the Feed Conversion Ratio (FCR) Calculator input fields.

Adjust settings. Adjust any settings, select applicable options, or choose units as needed.

Calculate the result. Press Calculate to compute the result using the underlying formula.

Interpret the output. Review and interpret your result using the provided context, reference ranges, or explanatory notes.

Glossary and Definitions

Physical quantity

A measurable property of a physical system, expressed as a numeric value with units.

Constant

A fixed, well-defined value (e.g. a CODATA constant) used across scientific calculations.

Significant figures

The digits in a measurement that carry meaning, reflecting the precision of the instrument.

Reference value

A published standard or experimental value used to validate a calculated result.

FCR calculator

A key concept referenced by the Feed Conversion: Calculate feed conversion ratio, feed efficiency, and residual feed intake for livestock production systems.

Feed conversion ratio

A key concept referenced by the Feed Conversion: Calculate feed conversion ratio, feed efficiency, and residual feed intake for livestock production systems.

Feed efficiency

A key concept referenced by the Feed Conversion: Calculate feed conversion ratio, feed efficiency, and residual feed intake for livestock production systems.

Livestock production

A key concept referenced by the Feed Conversion: Calculate feed conversion ratio, feed efficiency, and residual feed intake for livestock production systems.

Feed Conversion Ratio (FCR) Calculator

Formula Definitions

How to Use This Calculator

Glossary and Definitions

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