tgc: Thermal Growth Coefficient (TGC)

In aquacultuR: A Comprehensive R Tool for Zootechnical Metrics

Thermal Growth Coefficient (TGC)

Description

A function that calculates Thermal Growth Coefficient (TGC) based on the Initial Body weight (IBW) in grams (g), the Final Body Weight (FBW) in grams (g) and the average water temperature (Temp.) in Celsius (°C) for the duration of the trial.

The TGC is an alternative growth metric for fishes, describing the increase in bodyweight over a period of time. It is suitable for poikilothermic animals due to its standardisation for temperature. It should, however, be taken into account, that the temperature during the experiment should remain within the optimum range. It is also noteworthy that the equation is optimized for a constant temperature throughout the experiment.

Usage

tgc(ibw, fbw, duration, temp, scale_coef = 1000)

Arguments

ibw	a numeric value that is providing the initial body weight in grams.
fbw	a numeric value that is providing the final body weight in grams.
duration	a numeric value that is providing the duration of the experiment in days.
temp	a numeric value that is providing the average temperature during the experiment in degrees Celsius.
scale_coef	Scaling coefficient. A numeric value that scales the TGC result so it is more intuitive and interpretable. Default is 1000.

Value

Returns a numeric value that is the TGC.

Author(s)

Anıl Axel Tellbüscher

Davide A. Machado e Silva

Madhav Karthikeyan

References

Lugert, V., Thaller, G., Tetens, J., Schulz, C., & Krieter, J. (2016): A review on fish growth calculation: multiple functions in fish production and their specific application. Reviews in Aquaculture, 8, p.30–42.

Jobling, M. (2003): The thermal growth coefficient (TGC) model of fish growth: a cautionary note. Aquaculture Research, 34, p. 581–584.

aquacultuR documentation built on Jan. 26, 2026, 5:07 p.m.