Studies on the Physiological Responses of Rabbits to Ginger (Zingiber Officinale Roscoe) Rhizome Powder
Ogbuewu, I. P.
MetadataShow full item record
Four experiments were conducted to determine the physiological responses of New Zealand White rabbits to ginger rhizome powder (GRP) supplementation during pre-pubertal, pubertal and post pubertal stages of development. Firstly, GRP was analyzed to determine its proximate nutritional, amino acids, mineral and phytochemical compositions. Thereafter, it was included in commercial rabbit rations at the rate of 0 g (BT1 control), 5.0 g (BT2), 10 g (BT3) and 15 g (BT4) per kilogram of feed as supplement. In the second experiment, 72 pre-pubertal rabbits of equal sex distribution and aged 10 to 12 weeks were divided into four groups of 18 rabbits each and replicated three times in a randomized complete block design. They were fed the treatment diets for 12 weeks, while Panicum maximum and Centrosema pubescen were fed as additional fibre sources. Physiological responses were assessed using growth performance, hematology, serum biochemistry, carcass and organ characteristics. In the third experiment, 72 pubertal rabbits were divided into 4 groups of 18 each, which were again replicated three times in a completely randomized complete block design and suplemented with GRP at the same rates as the second experiment to determine GRP effects on selected male and female reproductive characteristics over a period of 10 weeks. In a fourth and final experiment, 72 post pubertal rabbits were similarlly used to determine GPR effects on growth performance, male and female reproductive and breeding characteristics, hematology, serum biochemistry over a period of 12 weeks. GRP analyses yielded mainly saponin (4.01 mg / 100g) and relatively low levels of proximate nutrients and amino acids. Predominant mineral elements were in the order of Na > K > Ca > P > Mn > Zn > Fe > Cu. At the pre-pubertal stage, the control, BT2 and BT4 recorded statistically similar final body weight (FBW), body weight gain (BWG) and feed conversion ratio (FCR) (p<0.05). The rabbits exhibited strong sexually dimorphism in their FBW and BWG values, which were significantly (p<0.05) different. Packed cell volume (PCV) and hemoglobin (Hb) values of BT2 and BT4 groups and white blood cell (WBC) and neutrophil counts of BT1 and BT4 groups were significantly influenced (p<0.05) by sexes. Serum cholesterol and triglycerides values of female BT4 group were generally statistically (p<0.05) higher than those of the males. At the pubertal stage, percentage live and dead sperm cells as well as live: dead sperm ratios were significantly (p<0.05) different in BT2, BT3 and BT4 groups. There were also significant (p<0.05) differences in % sperm motility between BT1 and BT4 groups. Control bucks had significantly (p<0.05) higher testicular weight than others. Ovarian weights were comparable (p>0.05) among the groups, with follicle stimulating hormone (FSH) value of BT4 and luteinizing hormone (LH) value of BT2, BT3 and BT4 being significantly (p<0.05) lower than those of the control. Estradiol-17ß values of BT2 and BT3 were equally significantly (p<0.05) different from those of the control and BT4 groups. Testicular histographs of supplemented groups revealed tissue degenerations. In the post - pubertal rabbit experiment, growth performance was significantly influenced (p<0.05) by GRP supplementation. Semen parameters values deteriorated with increase in GRP supplementation. Values of hematological parameters were generally within normal range. Significant sex effects (p<0.05) were however observed in PCV, WBC, lymphocyte, neutrophil counts serum cholesterol concentrations of BT3 and BT4 groups, as well as total serum protein values of BTI and BT4 and serum albumin and calcium value for BT4 rabbits. Serum 17ß - estradiol value of the BT1 does was significantly higher (p<0.05) than those in BT4 treatment group, while progesterone values increased with GRP supplementation and resulted in zero breeding in the BT3 and BT4 does. Testosterone concentration also increased with increasing GRA supplementation, with BT4 recording significantly higher values (p<0.05) than the control. The highest testicular weight was obtained in BT1 group whose values differed significantly (p<0.05) from BT3 and BT4 bucks. Histological assessment of the testes in BT2, BT3 and BT4 groups showed evidence of testicular degeneration. Overall results show that supplementation of up to 15 g / kg feed of ginger rhizome powder improved growth performance of rabbits but was associated with hormonal imbalance across sexes, reduced sperm quality and testicular degeneration in males and poor breeding performance in females. The growth improvement and contraceptive effects of ginger rhizome powder should be investigated for further exploitation of its benefits in animal production.