Dietary yeast-derived nucleotides enhance reproductive efficiency, blood metabolic profile, antioxidant status, and immune function in rabbit does.

Abstract

Yeast-derived nucleotides (YN) are gaining traction as high-value feed additives due to their proven multi-beneficial effects on the health and overall well-being of animals. Despite their proven efficacy, their specific impact on the reproductive performance of rabbit does remains poorly understood. This study investigates how dietary YN supplementation influences reproductive efficiency, hematological profiles, antioxidant status, blood health markers, and adipokine levels in rabbit does. A total of 120 nulliparous female rabbits were randomly assigned to four experimental groups (30 rabbit/group). The rabbits received either a basal diet (YN0, control) or supplemented with 0.25 (YN0.25), 0.5 (YN0.5), or 1 (YN1) g/kg of YN. Results showed that the YN-supplemented groups had significantly (P < 0.05) higher red blood cell (RBC) counts, platelet counts, total protein, and albumin levels compared to the control group. Dietary supplementation with YN led to a significant dose-dependent reduction in serum AST and ALT levels (P < 0.001). Similarly, concentrations of total lipids, creatine phosphokinase, haptoglobin, and lactate dehydrogenase (LDH) were significantly lower in all YN-treated groups compared to the control (P < 0.001). For cellular redox homeostasis, a significantly increased levels of TAC, CAT, GPx, and SOD, alongside a decrease in malondialdehyde (MDA) levels in rabbit fed diets with 0.25-1 g of YN (P < 0.05). A significant reduction (P < 0.05) was observed in serum inflammatory markers (toll-like receptor 4, and interleukin-4), the oxidative DNA damage marker 8-OHdG, and various circulating adipokines (leptin, adiponectin, visfatin, and irisin). In contrast, levels of immunoglobulins (IgM and IgG), interleukin-10 and reproductive hormones such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), and progesterone (PG) showed significant (P < 0.05) improvement in rabbits from the YN groups. The conception rate increased significantly across all YN-supplemented diets (P < 0.05), reaching its peak in the YN1 and YN0.5 groups at 83.11%, compared to 70.66% in the control group. Both litter size at birth and litter size at weaning were greater in rabbit fed 0.5-1 g of YN (P < 0.05). The findings of this study suggest that dietary inclusion of YN (0.5-1 g/kg) enhances hematological markers, antioxidant defense mechanisms, and reproductive hormone profiles. These improvements in productive traits were accompanied by a notable reduction in inflammation and a modulation of adipokine levels, contributing substantially to the rabbit industry.