The Growth Curves with Non-Linear Models of in Mixed-Sex of Caucasian Pheasants (Phasianus Colchicus Colchicus)

ABSTRACT The Caucasian pheasant (Phasianus colchicus colchicus) is a Phasianidae family poultry species that is an important animal-based protein source. This study aimed to estimate the growth traits of body weight (BW) in pheasants using Logistic (L), Gompertz (G) and Von Bertalanffy (VB) models. A total of 1,765 data records of BW from hatching to 18 weeks of age were collected from the pheasant population in the Alternative Poultry Unit at Prof. Dr. Hümeyra Ozgen Research and Application Farm, Selҫuk University, Türkiye. The results showed that the coefficient of determination (R2) value in each model was 0.94. However, the lowest values for Akaike’s information criterion (AIC) and Bayesian information criterion (BIC) among models were found in the G model. In general, the pheasants had the weight of inflection (Wi) and time of inflection (ti) of 535.11-592.00 g and 9.00-10.01 weeks, respectively. Moreover, about 80-90 g/week of the average weight gain was reached at the inflection point of the pheasants. In conclusion, the parameters of the goodness-of-fit criteria (AIC and BIC) indicated that the G model was the best formula to predict the growth curve of body weight in Caucasian pheasants.