ESR1 and salpingitis: In this study, ESR1 expression was highly modulated in the MLP-LPS group compared to the CN-LPS group, suggesting that MLP mitigates the damage of salpingitis on the reproductive performance of laying hens through high expression of ESR1. The uterus serves as the primary site for eggshell formation; thus the regulation of calcium was crucial in the uterus.