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Article History

Received: 6 March 2026

Accepted: 16 May 2026

First Online: 23 May 2026

Declarations

:

: The authors confirm that the ethical policies of the journal, as noted on the journal’s author guidelines page, have been adhered to. The research was approved by the ethical review committee at the Hebei Agricultural University (ethical approval number: 2021069). The guidelines of China for the Care and Use of Laboratory Animals were followed.

: The authors declare no competing interests.

: It was not feasible to track IgA levels in colostrum from the same sows continuously for three years as described in Section  , because sows in commercial herds are difficult to retain over three consecutive farrowing cycles. Sows are routinely culled due to declining reproductive performance or limb and hoof injuries. Nevertheless, sows included in the three-year monitoring were kept at a consistent parity across batches, which could reliably reflect the actual antibody levels in the corresponding batches.