Investigating the dose-response relationship of gum Arabic (Acacia senegal) in Ameliorating heat stress responses in rabbits

Escalating global temperatures are projected to intensify heat stress (HS), thereby posing a considerable challenge to the long-term sustainability and productivity of rabbit farming. Dietary supplementation with phytogenic feed additives, such as those possessing antioxidant properties, presents a promising strategy for conferring heat stress tolerance in growing fattening rabbits. This study aimed to investigate the impact of dietary Gum Arabic ( Acacia senegal ; GA) on growth performance, feed efficiency, carcass traits, hematological parameters, and antioxidant status in growing APRI-line rabbits breed during the summer season. The experiment involved a total of 90 weaning rabbits (35 days of age). The rabbits were randomly distributed into three equal experimental groups, each containing 30 rabbits. They received a basal diet containing 0 (control group), 2, and 4 g of GA/kg diet, respectively. The GA-treated groups exhibited significant enhancements in growth metrics, feed efficiency and dressing percentage. The rectal temperature linearly decreased in response to the dietary treatment ( P = 0.0001), while the respiration rate decreased quadratically, with the optimal dose at 2 g GA/kg diet ( P = 0.0185). Also, leukocyte and erythrocyte counts increased linearly with increasing levels of GA ( P = 0.0087 and < 0.0001, respectively). The dietary treatments resulted in a linear increase in blood protein and albumin levels. However, there was a quadratic diminution in the activity of the ALT enzyme ( P = 0.0040), with the optimal dose demonstrated at 2.5 g GA/kg diet. The concentration of serum creatinine decreased linearly due to dietary treatment ( P = 0.0003). The dietary interventions resulted in a notable improvement in the lipid profile, including total cholesterol and triglycerides. There were significant linear increases in the activity of serum superoxide dismutase ( P = 0.0105) and the levels of total antioxidant capacity in blood serum ( P = 0.0098) and liver tissue ( P < 0.0001). In contrast, the levels of malondialdehyde in blood serum and liver tissue showed a reverse linear trend ( P = 0.0068 and < 0.0001, respectively), while the activity of glutathione peroxidase improved quadratically ( P < 0.0001) in response to dietary supplementation, with the optimal dose at 2.5 g GA/kg diet. Dietary administration of rabbit diets with GA led to a quadratic increase in the levels of immunoglobulins M, G, and A ( P < 0.001), maximizing at 2.5 g GA/kg diet. In summary, adding GA (2.5–4 g/kg diet) can enhance growth performance, feed efficiency, redox status, and immune responses of growing rabbits during the summer season. • Heat stress induces significant reduction in the growth, blood metabolites, and immune dysfunction in growing rabbits. • Gum Arabia (GA) can improve the growth and feed efficacy in growing rabbits exposed to heat stress. • Stressed rabbits fed diets with GA (2 or 4 g/kg diet) significantly improved the health status and blood metabolites. • An improvement in the renal and hepatic histological examination after feeding stressed rabbits with GA.