Hematologic, lipid profile, immunity, and antioxidant status of growing rabbits fed black seed as natural antioxidants.

It is known that using antibiotics by way of growth promoters has harmful side effects on both animals and consumer health due to cross-resistance among pathogens and residues in meat. Using antibiotic to promote growth has been banned in the most countries for this reason; so, we must search for feed additives alternative in animal production. One of them is the black seed (Nigella sativa). Fifty-four growing V-line unsexed rabbits, 4 weeks of age, with an average weight of 776.7 g were randomly allocated to one of three treatments (n = 18): rabbits fed the basal diet (control), rabbits supplemented with either 300 or 600 mg of Nigella sativa seed (NSS)/kg diet. At 12 weeks of age, NSS supplementation significantly improved final body weight, weight gain, feed conversion ratio (FCR), and performance index with significantly reduced feed consumption. Addition of 300 and 600 mg NSS/kg diet resulted in a significant increase in the number of RBCs and WBCs as compared to basal diet group. Compared to controls, NSS supplementation significantly stimulated the IgG and IgM immune responses of rabbits, significantly reduced serum total lipids, triglycerides, and low-density lipoprotein, and significantly increased the high-density lipoprotein concentration. All NSS treatments significantly increased the observed blood total antioxidant capacity and significantly decreased the malondialdehyde values, compared to the basal diet group. In conclusion, the results displayed that addition of NSS in rabbit diets improved productive performance, blood lipid profile, immunity, and antioxidant status, and supplementation with 600 mg/kg NSS was more effective than 300 mg/kg NSS seed supplementation.