changes of cecal bacterial composition in laying hens exposed to different sounds and housed at different density

This study investigated the effects and interactions of sound sources (natural sound, music, and mixed road noise) and stocking densities (low, medium, and high density) on the laying performance in Xiandao green-shell layers. The experiment lasted 24 days. Based on the treatment of three sound sources and three stocking densities, the hens were randomly assigned to nine groups. Birds in three henhouses were exposed to natural sound (NS), instrumental music sound (MS), and mixed-road sound (RS). According to the combinations of sound source and stocking density, there were nine groups designated as NL (NS and LD), NM (NS and MD), NH (NS and HD), ML (MS and LD), MM (IMS and MD), MH (MS and HD), RL (RS and LD), RM (RS and MD), and RH (RS and HD). The cecal bacterial composition was analyzed through the 16S rRNA amplicon sequencing.