The current study aimed to evaluate effects of oral administration with different levels of Spirulina platensis on reproductive performance, hematological and biochemical criteria, antioxidant activity, and liver and kidney histogenesis of APRI doe rabbits. A total of 45 nili-parous does at 16-18 wk of age was allotted to 3 groups (15 does / group). Does in the 1st, 2nd and 3rd groups were daily received oral 3 ml distilled water containing 0 (G1) as control group, 300 (G2) and 600 (G3) mg/doe from Spirulina platensis for four weeks as a treatment period, respectively. At end of treatment, does were naturally mated by15 untreated fertile APRI bucks (5 bucks / group). Body weight (BW) of does, as initial and final of treatment (16-18 and 20-22 wk of age, respectively) and at kindling (22-26 wk of age), and of bunnies at birth and weaning were recorded for one parity. Daily feed intake (DFI) of does was recorded during treatment period. Conception (CR) and kindling (KR) rates and litter size (LS, total and live) of does, and bunny viability rate (VR) at birth and weaning were calculated. Plasma concentration of estradiol 17-β (E2) and progesterone (P4) of does on day 15 post-mating, hematological parameters, plasma biochemical and oxidative capacity at the end of treatment, and hepatic and renal histology of does at the end of experiment were determined.
Results showed that doe final BW was heavier (P<0.05) in G2 than in G1 and G3. Change in BW (absolute or relative to initial BW), DFI, CR and LS of does, and VR and BW at birth and weaning of kids increased (P<0.05) in G2 and G3 than in G1, but KR was similar. Plasma E2 and P4 was higher (P<0.05), while E2/P4 ratio was lower (P<0.05) in G2 and G3 than in G1.
Only E2 was higher (P<0.05) in G2 than in G3. Values of hemoglobin, red blood cells hematocrit, neutrophils and eosinophils increased (P<0.05) in G2 and G3, while platelets and lymphocytes, monocytes and acidophils decreased (P<0.05) in G2 and G3 compared with G1. The white blood cells decreased (P<0.05) only in G2, while erthrocytic values were not affected. Plasma total proteins, albumin, globulin and high density lipoprotein increased (P<0.05) in G2 and G3, while total lipids, triglycerides, total cholesterol and low density lipoprotein, aspartate aminotransferase, alanine aminotransferase, acid phosphatase and alkaline phosphatase decreased (P<0.05) in G2 and G3 compared with G1. Blood total antioxidant capacity, glutathione S-transferase, superoxide dismutase, glutathione and glutathione peroxidase increased (P<0.05), while thiobarbituric acid-reactive substances decreased (P<0.05) in G2 and G3 than in G1. Hepatic and renal tissues of treated does were normal.
In conclusion, orally administrated Spirulina platensis (300 mg/doe) as natural antioxidants was proved to improve reproductive performance, blood constituents, antioxidative status without adverse effects on liver and kidney functions.