| “Yufen I” is a native egg-laying chicken breed, which was raised by three-line cross. The new breed was cultivated by Henan Agricultural University. The experiment was applied to compare the growth rules, laying performance and egg quality of yufen I commercial line. In order to study the production characteristic of yufen I commercial line, which including growth rule, egg production performance and egg qualities, This paper discuses that the three Curve Fitting Method of animal growth can be used to predict the growth of yufen I, which include Logistic, Gompertz and Von-bertalanffy model. The two characters of body size and weight were analyzed by using simple correlated coefficient and path analysis The weekly laying rate date of yufen I hens commercial line was fitted by three mathematical models, including Wood model, Mc Millan model and Yang model. Then, the one-way analysis of variance was used to compare egg qualities. The main results are as follows: Experiment 1: weight curve fitting of yufen I commercial line in 0-22 weedsThe results showed that Gompertz model showed the best simulating effect, and the degree of fitting was 99.89%. The terminal body weight was 1205.8 g, and the inflexion was 443.5 g and 10 week. As a new varieties of laying hens, the growth is very fast at the early stage of the growth. The experiment was conducted to study the changes of bodyweight. The model could be the laying rules of the yufen I layer and could take it as the theory growth curve. Experiment 2:Correlation analysis of weight and body size in different weeks.Body size and weight of yufen I commercial line were measured at 6 weeks, 14 weeks and 20 weeks of age. The results showed that Body weight was positively correlated with body size in yufen I commercial line(P<0.05). Along with the weeks change, the degree of correlation became different. The high correlation ships were found between the body length and body weight of the yufen I commercial line at 6 weeks, phalanx length followed by, chest angle and thud width were the least(under 0.29); phalanx circumference were the highest correlation coefficient in all, the body length was middle correlation ships, phalanx length, chest depth and chest angle were least at 14 weeks.The correlation of weight and body size at 20 week was similar to 14 week. High path coefficients from size of body to weight were the phalanx length and body length at 6 weeks. The least was thud width; the phalanx circumference and body length was the highest at 14 weeks. At 20 weeks, the thud width was the highest. We inferred the body length and phalanx length were the main facts in the early stage of the growth. At least, the thud width was the significant factors.In view of this, choice of earlier period of growth for yufen I should be more for body length and phalanx length; The latter, should be devoted to strengthen the thud width. These results of trial provide significant data and basic information. For further research on yufen I commercial stock and related genetic research of Gallus. Experiment 3: Laying law curve fitting of yufen I commercial lineThe results show that the climax of egg laying appears at the 7th week after the first laying and some at the 8th week. The highest egg laying rate can reach at 60% about 18 weeks. Then the egg laying rate gets a slow decrease period.The weekly laying rate date of yufen I hens commercial line was fitted by three mathematical models,including Wood model, Mc Millan model and Yang model. The characteristics of these three mathematical models were calculated by R2 value. The results of the three fittings were different with R2 values ranged from 0.58 to 0.95. Among which, the R2 value of Mc Millan model was the largest. It is concluded that Mc Millan model(R2=0.987) is the optimum model of egg production for high quality hens. Experiment 4: the one-way analysis of variance was used to compare egg qualities in differen-t weeks100 eggs, which were produced by yufen I commercial line at 32.36.40 weeks,were detected.The result shows that: eggs quality indicators of yufen I commercial line have different degree of change at different weeks. Average egg weight is 51.3 g. It is significantly lower than the normal brown shell laying hens. Egg yolk, egg yolk ratio and egg shell thickness were 14.1 g, 27.69% and 0.35 mm. Hartz unit is 76.69,it had reached AA grade. Eggshell intensity reached 4.765 kg/m2, which has high strength. It has very important significance for the industrial production. The same way as normal egg, egg index of yufen I is 1.27. The egg yolk color is 8.72. It is darker than ordinary eggs. This characteristic were greatly extruded the advantages of local chicken.With the increase of weeks, egg egg weight, egg yolk, weight, eggshell strength, hartz unit, thick albumen height, egg yolk color have significant differences. Egg weight. Egg shell weight were increase first and then decrease when the weeks increased. Egg yolk, hartz unit, thick albumen height and eggshell intensity were increased with developing the weeks. Egg-shaped index and egg yolk ratio had no significant change with the increase of the weeks. Shell thickness and the egg yolk color were changed irregularly... |
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