The Effect of Calsporin^® (Bacillus subtilis C-3102) on Laying Performance, Follicular Development, and Microorganisms of Breeder Geese

This study aimed to investigate the effects of Bacillus subtilis C-3102 (CAL) on the laying performance, follicular development, and cecal microorganisms of breeder geese. The experiment was conducted at a goose farm in Lu’an City, Anhui Province, from April to December 2024. A total of 5965 geese (male-to-female ratio of 1:4.75) were used and divided into three groups with CAL supplementation levels of 0 ppm, 60 ppm, and 100 ppm. Changes in laying performance, serum hormones, follicle number, and fecal microorganisms were analyzed. The results showed that, compared with the control group, the total number of eggs laid in the 100 ppm BS group increased by 2.77 eggs (p < 0.05), and the number of graded follicles was significantly increased by 78.2% (p < 0.05). There was no significant difference in serum reproductive hormones among all groups (p > 0.05). Microbial analysis revealed that the 100 ppm CAL group had a significantly higher abundance of Firmicutes, with enrichment of the genera Bacillus and Lactococcus. Additionally, the relative abundance of Bacillus was significantly positively correlated with the level of intestinal secretory immunoglobulin A (sIgA) (p < 0.05). However, the egg weight and egg shape index in the 60 ppm CAL group were significantly lower than those in the other groups (p < 0.05), and there was no significant difference in hatching rate among all groups (p > 0.05). This study indicated that CAL has precise application value in the green breeding of breeder geese. It is recommended to add CAL at a dose of 100 ppm, which can improve the laying performance and optimize the follicular development of breeder geese by enhancing intestinal microecology and mucosal immune function. The results provide a direct theoretical basis and practical reference for the scientific application of CAL in breeder goose breeding.