Effects of incompletely degraded galactomannan on growth performance and immune function of cyclophosphamide-induced immunosuppressed broilers

Intensive broiler farming frequently leads to immunosuppression, causing substantial economic losses. Galactomannan, derived from various plants, exhibits potent immunoregulatory properties; however, its bioavailability is limited by its high molecular weight and complex structure. In this study, we prepared incompletely degraded galactomannan (IDGM) from Sesbania seeds using an enzymatic method and explored its effects on growth performance and immune function in cyclophosphamide (CTX)-induced immunosuppressed broilers. Our results showed that IDGM significantly increased (P < 0.05) the average daily gain (ADG) from d 1 to d 14, and reversed (P < 0.05) the CTX-induced reduction in ADG from d 15 to d 21, as well as in the average daily feed intake (ADFI) during d 15 to d 21 and d 22 to d 42. In addition, IDGM counteracted (P < 0.05) CTX-induced decreases in spleen and thymus indices and in interleukin-2 levels in plasma at the age of d 21 and d 42. Furthermore, IDGM alleviated histopathological damage, restored (P < 0.05) the CD4⁺/CD8⁺ ratio, and modulated (P < 0.05) Th1/Th2 balance in the spleen of CTX-challenged broilers via the c-Jun N-terminal kinase/p38 mitogen-activated protein kinase signaling pathway. Collectively, these findings indicate that IDGM effectively improves growth performance and mitigates CTX-induced immunosuppression in broilers.