Gompertz growth curves of body weight and phalanx length,and regression analysis in Zang chicken

The body weight and phalanx length of Zang chicken were measured at the age of hatching to twenty-week and the growth curves were analyzed with Gompertz model.The results showed that the Gompertz model was fitting to growth of Zang chicken.The parameters of the model indicated that the male chickens had higher adult body weight,initial growth rate,inflection point body weight,and inflection point time than the female,but the differences between the male and the female in adult phalanx length and inflection point phalanx length were insignificant.The body weight or phalanx length at the age of six-week correlated with later body weight markedly,so it could be used to estimate the later body weight of Zang chicken,and be one of traits for selecting early.