ABSTRACT: The objective of the study was to assess the effect of diets supplemented with Ziziphus spina-christi leaf on digestive fermentation, antioxidant status, and haemato-biochemical indices of growing rabbits. Ziziphus leaves (ZLs) of Ziziphus spina-christi were collected from Sidr trees scattered throughout the city of Medina, Saudi Arabia. Three formulated diets containing 0, 10, and 20?g Ziziphus spina-christi/Kg diet as supplementation were offered ad libitum. The organic matter content of ZL was higher. Chemical compositions were comparable in all of the contents of the tested diet. Quantities of gas released from the control diet were higher, and then the gases released decreased significantly (P < 0.05) with the addition of ZL. The values of NH3-N were taken as the same trend. The addition of a high level of ZL to rabbit diets led to a decrease (P < 0.05) in the total count of bacteria as well as the number of E. coli and Clostridium spp. However, the number of Enterococcus bacteria was not affected by supplementation. Haemoglobin parameters of the control group and groups 2 and 3 were compared: white blood cell count and red blood cell count. These observations of total protein and albumin within the range of reference values were reported in healthy rabbits, while glucose significantly decreased with the addition of ZL and AST in the blood increased significantly. The values of TP, albumin, and ALT measurements showed no significant differences among groups fed on test diets. Significant differnces in serum immunoglobulins were observed between the groups, while the high levels of ZL supplement led to a significant (P < 0.05) increase in the serum IgA, IgG, and IgM levels. Antioxidants expressed as T-AOC, GSH-Px, T-SOD, and CAT in the blood of animals fed on diets containing high levels of ZL were significantly higher. Higher serum T-AOC, T-SOD, and CAT activities were observed in rabbits supplemented with a high level of ZL compared with the control group (P < 0.05). The supplementation of ZL tended to increase serum GSH-Px activity. The addition of ZL to rabbit diets led to an increase in dry matter intake. On the other hand, there was no significant change in the apparent digestion coefficient of DM, OM, CP, and fat. Conclusion. Dried ZL supplementation up to 20?g/Kg diet might improve the bacterial community, antioxidants, biochemical parameters and blood constituents of rabbits, and digestibility.
