Objective Frizzle chicken and Huaixiang chicken are excellent local breeds produced in the west of Guangdong. The early growth and development rules of the two local breeds of chickens are explored so as to provide a theoretical basis for the protection, development and utilization of their resources.

Method By measuring the body weights of Frizzle chickens and Huaixiang chickens aged 0-16 weeks, Logistic, Gompertz and Bertalanffy models were used for fitting analysis of their growth.

Result The fitting degree of the fitting curve of three models was above 0.979, and the fitting degree of Huaixiang chicken was generally better than that of Frizzle chicken; the fitting degree of Logistic model was poor, while the fitting degree of Bertalanffy model was the highest for Frizzle chicken and Huaixiang chicken, and it could better describe the actual growth situation of Huaixiang chicken. The ages of growth inflection point of Frizzle chicken and Huaixiang chicken fitted by Bertalanffy model were 11.4 weeks and 5.8 weeks respectively, and the weights of growth inflection point were 894.1 g and 498.7 g respectively. The growth curve equation of Frizzle chickens was as follows: Y=3017.521×〔1-0.726exp(-0.068t)〕³, and the growth curve equation of Huaixiang chickens was: Y=1683.001×〔1-0.787exp(-0.147t)〕³.

Conclusion Bertalanffy model is suitable for the growth curve fitting of Frizzle chickens and Huaixiang chickens, and the corresponding growth curve and key parameters are obtained through the analysis of the growth and development rules, which provides a certain scientific basis for the resource protection, breed selection and industrial development of the two local chicken breeds.