Abstract: This study aimed to explore potential optimization of the immunization program for Chenzhou Runyang Ecological Agriculture Co., Ltd. in Hunan Province while maintaining dual-negative status for PRRSV and African swine fever virus (ASFV), and antigen-negative status for Pseudorabies virus (PRV). Classical swine fever virus (CSFV), Foot-and-mouth disease virus (FMDV), Transmissible gastroenteritis virus (TGEV), Porcine epidemic diarrhea virus (PEDV), and Mycoplasma under existed immunization protocols. A total of 224 serum samples were collected from sows and growing pigs at the breeding farm. In-house testing methods were employed to analyze antibodies against Porcine circovirus (PCV) and Mycoplasma in sows of different parities and growing pigs at various weeks of age. Results showed that high Porcine circovirus protective Cap antibody levels across all sow parities with 100% antibody positivity, indicated robust immune protection. Notably, high-titer Porcine circovirus infectious Rep antibodies were observed only in individual high-parity sows, while most exhibited low-level Rep antibody presence. All growing pigs maintained protective antibodies across age groups, with Porcine circovirus infectious Rep antibodies detected in all weeks except the 12th week, though at relatively low titers. Low-level Mycoplasma hyopneumoniae antibodies were detected in sows across parities, attributed to infections occurring between the gilt stage and first parity stage. In growing pigs, Mycoplasma vaccination elicited immune responses with modest antibody levels. Post-28 weeks, despite natural Mycoplasma exposure, no significant antibody surge occurred, suggesting partial vaccine efficacy in suppressing subsequent infections. Based on current immunization protocols, antibody dynamics, and clearance patterns, we proposed program adjustments including optimized vaccination timing and enhanced booster regimens to strengthen disease prevention in this breeding operation.

Key words: breeding pigs, circovirus, Mycoplasma pneumoniae, sow breeding farm, immunization program, detection