Comparison of Compertz and Logistic Models in Estimating the Growth of Leptin-Deficient (ob/ob) Mice and Wild-Type Mice Fed an In-House Prepared High-Fat Diet

Abstract

This experiment was conducted to growth curve models for leptin-deficient (ob/ob) and wild-type mice fed a meal-form High-Fat (HF) diet prepared in-house for over 120 weeks. Two hundred and twenty-four sets of Body Weight (BW) and age data were collected from ob/ob mice and 485 sets of data were collected from wild-type mice. All animals had free access to the HF diet (34.3% energy from fat) and water. Individual BW and survival rates of mice were measured. To develop growth curves of ob/ob mice and wild-type mice fed the HF diet, Gompertz and Logistic growth models were employed. The survival rates of ob/ob mice fed the HF diet were lower than those of wild-type mice. Models for estimating growth of ob/ob mice fed the HF diet were: BW, g = 61.36 × e^{-2.56×e^-0.13t} in Gompertz model (Akaike’s Information Criterion, AIC = 1,694); and BW, g = 60.65 × (1 + 7.04 × e^-0.18t)^-1 in Logistic model (AIC = 1,719). Growth models for wild-type mice fed the HF diet were: BW, g = 28.94 × e^{-1.75×e^-0.13t} in Gompertz model (AIC = 3,171); and BW, g = 28.23 × (1 + 4.85 × e^-0.25t)^-1 in Logistic model (AIC = 3,198). In conclusion, Gompertz models may be more appropriate to estimate the growth of ob/ob mouse fed the diet with high-fat concentration.