Seyed Yavar Heydari; Nasrollah Pirany; Behnam Ahmadipour; Mohammad Reza Akbari
Volume 22, Issue 3 , September 2020, , Pages 441-455
Abstract
This study was conducted to investigate the weight changes, age and weight at first laying, the outer and inner egg characteristics of breeding station of Isfahan native chickens. Three hundred-day old native chickens were used in this survey. The experiment was started from the first day to the end ...
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This study was conducted to investigate the weight changes, age and weight at first laying, the outer and inner egg characteristics of breeding station of Isfahan native chickens. Three hundred-day old native chickens were used in this survey. The experiment was started from the first day to the end of 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 and 2061.46 g, respectively. The overall average of the egg weight was 45.47 g in whole production period. The average number of eggs produced by each 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 and yolk 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 shell weight 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 was negative and significant (P <0.05). The results of this experiment indicated the good production potential in some of these birds which proper breeding programs may led to improve their productivity.