Modelling gastric evacuation without meal size as a variable. A model applicable for the estimation of daily ration of cod (Gadus morhua L.) in the field

• Published in: ICES Journal of Marine Science
• Main Authors: Temming, Axel, Andersen, Niels Gerner
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1994
• Subjects: Gadus morhua
• Online Access: https://orbit.dtu.dk/en/publications/b4d38d3e-2f10-4514-b353-674839365cf6; https://doi.org/10.1006/jmsc.1994.1044

Data on gastric evacuation of cod from the International Data Base on Gastric Evacuation Experiments have been reanalysed. A general evacuation models was fitted to the data by means of non-linear regression techniques: dS/dt= - R × SB or integrated:| S(1 - B) t=S1)(1 - B) - R × (1 - B) × 1, where S=stomach content, T=time after ingestion, R and B=constants. This model allows for various curve shapes, including linear (B=O) and exponential (B=1), and the curve shape (B) was estimated from the data. Meal size was included in the model by modifying the constant R=R′ × MD, with M=meal size in weight and D=constant. When meal size was included in the model, the resulting B values were strongly dependent on the food type and the estimated D values were negatively correlated with B: capelin, B=1.37, D= -1.16; herring, B=0.84, D= -0.57; and prawn, B=0.35, D= -0.14. When meal size was excluded from the model, the resulting B values were closer together (capelin, 0.47: herring, 0.43; and prawn, 0.27), the loses in explained variance, however, were small (capelin, 4% herring, 1%: and prawn