Model parameters of growth curves of three meat-type lines of Japanese quail

Abstract

This study was focused on a comparison of the growth characteristics and parameters of three meat-type lines of Japanese quail. The body weight data of wild-type, dotted-white and extended-brown quail lines over time were collected and fitted to Richards equation. The relevant parameters were compared based on the Confidence Interval Test. Confidence Interval Test calculates the percentages of model predictions staying in the confidence intervals of the corresponding experimental data. Both sexes of brown quails showed lower weight gains than the other two lines. Behind the inflection point a decline in the absolute growth rate was slowest for brown females. In general, Richards model parameter values showed deviations of one line from the other lines to a varying extent. Shape parameter for males (0.335-0.618) and maturation index for females (0.067-0.077) tend to be the most critical parameters. When the overall models were used to predict the weight of other lines, the models of white and wild males showed great similarity. Overall model predictions for male brown and white quails, for female brown and wild-type quails showed the largest differences. Like in males, white and wild females were the closest lines but the likeliness percentage was lower than that for males. The proposed method of parameter comparison can be a useful tool for researchers working on biological modelling.

Keywords

• quail
• growth curve
• richards function
• nonlinear model parameter comparison