Abstract: This application provides a signal transmission method and apparatus. The method includes: A collaboration device receives a synchronization trigger frame delivered by a central device; the collaboration device obtains information about a time domain offset and/or information about a frequency domain offset; and the collaboration device sends a signal based on the synchronization trigger frame and the information about the time domain offset and/or the information about the frequency domain offset by using a corresponding time domain resource and a corresponding frequency domain resource. In this way, a plurality of collaboration devices send different time domain resources and/or frequency domain resources to a same terminal, and an interfering signal in channel estimation can be removed. This improves precision of the channel estimation and noise estimation at a receiving end, and improves demodulation performance at the receiving end and entire-network throughput.

Abstract: A breeding method for improving reproductive performance of a chicken specialized dam line includes the steps of forming an F1 generation group, forming a breeding group, screening a breeding group, forming an F2 generation group, and continuously breeding to an Fn generation group. The method includes raising in small-scale groups and natural mating for systematic selection and breeding, which effectively reduces the generation interval and has the features of easy operation and fast genetic progress, not only ensuring animal welfare, but also effectively improving production performance.

Abstract: A breeding method for improving reproductive performance of a chicken specialized dam line includes the steps of forming an F1 generation group, forming a breeding group, screening a breeding group, forming an F2 generation group, and continuously breeding to an Fn generation group. The method includes raising in small-scale groups and natural mating for systematic selection and breeding, which effectively reduces the generation interval and has the features of easy operation and fast genetic progress, not only ensuring animal welfare, but also effectively improving production performance.