The development rule of feathers and application of hair root tissue in sex identification of Yangzhou geese.

Accurate gender identification is crucial for the study of bird reproduction and evolution. The current study aimed to explore and evaluate the effectiveness of a noninvasive method for gender identification in Yangzhou geese. In this experiment, 600 goose eggs were collected. Hair root tissues were used for PCR amplification, molecular sequencing, and anal inversion for early sex recognition in goslings. According to the DNA amplification results for the feather pulp tissue of 2-wk-old geese, bands appeared at 436 bp (CHD1-Z) and 330 bp (CHD1-W) upon gel electrophoresis. This method considered the base of goose feathers to accelerate the process of gender recognition. By examining the sex of anatomized poultry for verification, the accuracy rate of PCR gel electrophoresis and molecular sequencing sex identification was 100%, whereas the average accuracy rate of anal inversion was 97.41%. In the comparison of feather growth trends at 0 to 18 wk of age, the feather root weight (FRW), feather root length (FRL), feather branch length (FBL), and feather shaft diameter (FSD) of Yangzhou goose of the same age were not significantly different between males and females (P > 0.05). At 6 wk of age, the FRW, FRL, and FSD in males and FRL in females increased rapidly; their growth increased by 84.43, 67.58, 45.10, and 69.42%, respectively. At 10 wk of age, the male FRL, male FBL, and female FBL increased by 37.31, 34.81, and 21.72, respectively. The Boltzmann model was found to be the best-fitting model for the feathers of male Yangzhou geese. Early sex identification based on feather growth trends between the sexes is not feasible. This study provides a convenient and reliable technical means for early sex identification of waterfowl and serves as an ecological strategy for protecting the reproduction of poultry populations.