Broodiness, egg production, and correlations between broody traits in an indigenous chicken breed

摘要

The influence of broodiness on egg production was evaluated, and correlations between the age of the first broody cycle (AFB), duration of first broody cycle, and interval between the end of the first broody cycle and the re-laying of eggs were calculated in Chinese Qingyuan (Q line) chicken. In addition, age at first egg and individual egg production were recorded. From a single hatch, hens were randomly divided into 2 groups, group A (n = 576) and group B (n = 576). Group A hens were allowed to go through the entire broody cycle, whereas group B hens were treated so as to interrupt the cycle. Mean incidence of broodiness was approximately 15%, with the average AFB at approximately 40 wk (i.e., about 20 wk after the onset of lay). Nonbroody hens produced more eggs than broody and treated hens. However, a higher laying rate during the nonbroody period partially compensated the egg loss from broodiness. Negative correlations (P < 0.01) were found between AFB and duration of first broody cycle or interval between the end of the first broody cycle and the re-laying of eggs, indicating that the age of the first broody cycle can be regarded as a phenotypic marker for intensity of broodiness in hens.