Study on Growth Regularity of Body Weight,Shank Length and Small Intestine of Jinghong Laying Hens and the Fitting of Growth Curve

The objective was to study the growth and development rules of weight,shank length and small intestine of Jinghong laying hens.The growth curve of weight,shank length and small intestine of Jinghong laying hens from 0 to17 weeks old was analyzed and fired with three kinds of nonlinear models(Logistic,Gompertz,Bertalanffy).The results showed that the bertalanffy model had the best effect on fitting with the growth curves of weight.Its Bertalanffy growth function was y =2722.069 ×(1-0.756e~(-0.079t))~3,the inflecttion week,the inflexion body mass and the maximum week growth value described by the Bertalanffy model was 806.54 g,10.37 week and 95.57 g.The Logistic model had the best effect on fitting with the growth curves of duodenum,the Bertalanffy model had the best effect on fitting with the growth curves of jejunum and ileum.The Logistic model had the best effect on fitting with the growth curves of shank length.Its Logistic growth function was y=9.782/(l+2.985×e~(-0.3t)),the inflecttion week,the inflexion body mass and the maximum week growth value described by the Logistic model was 4.89 cm,3.65 week and 0.73 cm.It was feasible to analyze and fit the growth curve of the Jinghong laying hens using the three models.Different evaluation index to determine the optimal model was different,according to the most appropriate model analysis the growth and development rules can provide reference to understand the Jinghong laying hens.