PSPH and pancreatitis: Infection with pancreatitis-associated DHAV-1 caused yellowing and hemorrhagic lesions in the pancreatic tissues of ducklings and was associated with differences in the expression levels of D-3-phosphoglyceratedehydrogenase, phosphoserine aminotransferase, and phosphoserine phosphatase, which are involved in the glycine, serine, and threonine metabolism pathways.