Survey on laying performance and egg characteristics of native hens from Isfahan breeding station

This study was conducted to investigate the weight changes, age and weight at first laying, the outer and inner egg characteristics of breeding stationof Isfahan native chickens. Three hundred-day old native chickens were used in this survey. The experiment was started from the first day to the endof the 12 weeks of egg production (32 wks. of age). The results indicated that average age and weight of the first laying hens were 152.6 days and2061.46 g, respectively. The overall average of the egg weight was 45.47 g in whole production period. The average number of eggs produced byeach hen in 12 weeks of production period was 42. The range of hen production percentage in each week was 5.83 to 61.99 with an average of 45.44.The regression curves of height and diameter of yolk with production weeks were in order of second; with the weight of the hen's body, the white andyolk weight, and the shell thickness were of third order and with the rest of the traits were in forth order. Correlation of age at first egg with shellweight was high (r =0.99) and highly significant (P <0.001), but with total egg weight, the length and weight of the egg, and the height of yolk wasnegative and significant (P <0.05). The results of this experiment indicated the good production potential in some of these birds which proper breedingprograms may led to improve their productivity.