INFLUENCE OF CHLORELLA VULGARIS SUPPLEMENTED DIETS ON OXIDATIVE STRESS AND REPRODUCTION PERFORMANCE OF NEW ZEALAND WHITE RABBITS

Abstract

This study investigated antioxidant capacity of microalga Chlorella vulgaris on oxidative stress attenuation for improved reproduction in rabbits. The study commenced with an in vitro evaluation of the microalga as a source of antioxidants followed by supplementation of 0, 200, 300, 400, and 500 mg Chlorella vulgaris biomass per kilogram bodyweight of rabbits in groups designated as Control, T1, T2, T3, and T4 respectively in studies cutting across the different physiological states including pre-pubertal, gestation, lactation, and finishing stages. Forty weaner rabbit does each were studied for the prepubertal, gestation and finishing stages, while 35 and 75 rabbit does and male rabbit kits of the does were studied during the lactation and prepubertal stages respectively. The experimental design implemented at each of the physiological stage was completely randomized design. The animal management practices include the provision of individual housing for the rabbits in cages, ad-libitum provision of basal feed, and water, and provision of kindling boxes towards period of parturition. Data on the rabbit’s performances, serum, and tissues oxidative stress biomarkers were obtained while in addition, patterns of regulation and expression of genes associated with oxidative stress, reproductive performance, immune, and growth regulations were determined in the rabbit kits and the weaner rabbits reared from weaning to finishing stage. The microalga intakes improved reproductive index of the rabbit does whereby the group with highest intake of the microalga had a reproductive index of 7.00 against the control which had a reproductive index of 5.36 (p = 0.01). Serum gestational malondialdehyde concentration was reduced because 13.54, 14.05, 11.82, and 13.54 nmol/mL were determined in the serum of rabbits in the groups T1, T2, T3, and T4 respectively, against 28.85 nmol/mL determined in the serum of rabbits in the control group during the gestation period (p = 0.003). The microalga intake reduced feed intakes without reduction in commercial carcass yield and feed to meat production of the rabbits studied till finishing stage (p = 0.001). The supplementation of the microalga led to the up-regulation of genes including SOD1, GPX1, GSTP1, and CYP1A1 in rabbits of the treatment groups against the control (p = 0.05). Furthermore, gestational maternal intake of the microalga led to kindling of rabbit kits with higher birthweights whereby 40.22, 39.33, 41.73, and 50.23 g, were recorded for the kits kindled by rabbits in T1, T2, T3, and T4 respectively, against 34.89 g, for the Control (p = 0.04). Following the analyses of the recorded data, it was concluded that supplementation of Chlorella vulgaris biomass in rabbits at different physiological states protected the rabbits against oxidative stress and led to improved reproductive index, higher productivity, and growth. Therefore, intakes of the microalga biomass at 200, 300, 400, and 500 mg per kg bodyweight of rabbits were recommended as suitable dosages for performances improvement in rabbits from pre pubertal to finishing stages.