Haematological and Serum Biochemical Indices of Growing Rabbits Fed Diets Containing Varying Levels of Moringa oleifera Leaf Meal

Aims: To determine the influence of Moringa oleifera leaf meal (MOLM) on haematological and serum biochemical indices of growing rabbits fed diets containing varying levels of Moringa oleifera leaf meal. Study Design: Completely randomized design. Place and Duration of Study: At the Rabbit unit of the Teaching and Research farm of Federal College of Agriculture, Ishiagu, Ivo L.G.A., State, Nigeria, between May, 2015 and July 2015. Methodology: 48 growing rabbits were used for this study. Four diets were formulated such that diets T1, T2, T3 and T4 contain MOLM at 0%, 10%, 20% and 30%, respectively. The diets were offered to the growing rabbits, which were randomly divided into 4 groups of 12 rabbits each, with 4 animals constituting a replicate in a completely randomized design pattern. Each animal received the experimental diet for 49 days. Blood samples were drawn from each animal on the last day of Original Research Article Jiwuba et al.; BBJ, 15(2): 1-7, 2016; Article no.BBJ.28095 2 the trial and evaluated for haematological and serum biochemical indices, data obtained were analysed statistically. Results: Results showed that packed cell volume (PCV), haemoglobin Mean cell haemoglobin concentration and white blood cell differed (P<0.05) significantly, while red blood cell, mean cell haemoglobin and mean cell volume were similar (P>0.05) among the groups PCV ranged between 35.01–36.59%. Haemoglobin was improved (p<0.05) by Moringa oleifera leaf meal at 30% inclusion level. White blood cell (WBC) count of weaner rabbits in treatment groups was significantly (p<0.05) higher and better than the control. All the serum biochemical indices were significantly (P<0.05) except creatinine. Cholesterol was lowest at 30% inclusion indicating the antidiabetic properties of the test ingredient. Conclusions: All the parameters studied fell within the normal range reported for clinically healthy rabbits; an indication that MOLM had a beneficial effect on health status of rabbits.


INTRODUCTION
Blood indices are considered to be critical indicators of the physiological stages of farm animal, thus reflecting the relationship between their nutrition and health. They are useful for clinical evaluation of various animal diseases and feed quality. According to [1] serum creatinine helps in evaluation of liver function and diseases while serum urea evaluates renal function. Packed cell volume and red blood cells help to determine the feed toxicity and anemia in farm animals. Blood parameters change in relation to the physiological status of an animal. These changes could be as a result of several factors such feeding level, feed quality, age, sex, breed, temperature and physiological status of animals. These differences have further underlined the need to establish appropriate physiological and nutritional baseline values for rabbits, which could help in realistic evaluation of the management practice, nutrition and diagnosis of health of the host animal.
The incorporation of protein from leaf sources in diets for rabbits is fast gaining grounds because of its availability, abundance and relatively reduced cost [2]. Leaf meals do not only serve as protein sources but also provide some vitamins, minerals and also oxycarotenoids. Studies have shown that multipurpose trees can be used as cheap protein source which can improve general performance of animals.
Moringa oleifera belongs to the single genus monogeneric family Moringaceae and is well distributed in Africa and Asia. Apart from being a good source of protein, vitamins, amino acids, and minerals for rabbits, they also have medicinal uses [3]. Moringa oleifera, has reputation for many medicinal properties, possesses hypocholesterolemic properties [4] and could serve as substitute for conventional feedstuffs [5]. The protein content of the leaves are high ranging between 20-35% on a dry weight basis and most importantly, the protein is of high quality having significant quantities of most essential amino acids [6]. The leaves are highly nutritious containing significant amount of Vitamins A, B, C, Ca, Fe, P and protein [7]. The tree has in recently been noted as an outstanding source of highly digestible protein, calcium, iron, vitamin C, and carotenoids suitable for utilization. However, data on haematological and serum biochemical parameters of rabbits fed concentrate from multipurpose tree such as M. oleifera are scanty. Therefore, this experiment was carried out to determine the influence of Moringa oleifera leaf meal (MOLM) on haematological and serum biochemical indices of growing rabbits.

Location of Experiment
The research was carried out at the Rabbit Unit, Federal College of Agriculture, Ishiagu, Ivo Local Government Area of Ebonyi State, Nigeria. The College is located at about three kilometers (3km) away from Ishiagu main town. The College is situated at latitude 5.56°N and longitude 7.31°E, with an average rainfall of 1653 mm and a prevailing temperature condition of 28.50°C and relative humidity of about 80%.

Sources and Processing of Experimental Material
Fresh leaves of Moringa oleifera were harvested within the College environment and air dried for some days to a moisture content of about 10%. The dried leaves were processed and milled.

Experimental Materials and Management
Forty eight weaner rabbits were randomly divided into four (4) experimental groups of twelve (12) animals each, with four (4) rabbits constituting a replicate. The four treatment groups were assigned the four experimental diets in a Completely Randomized Design. Each rabbit received an assigned diet for 49 days. The animals were provided with feeders and drinkers. Each animal was vaccinated against prevalence under current diseases and were quarantined for 21 days before the commencement of the experiment. They were also dewormed and given accaricides bath prior to the experiment.

Experimental Diets
Four diets, T1, T2, T3 and T4 were formulated from maize, wheat offal, soybean, fish meal, palm kernel cake, Moringa oleifera leaf meal, bone meal, limestone, vitamin premix, methionine, lysine and common salt. Treatment one (T1) did not contain the test ingredients, thereby serving as the positive control. The experimental diets were formulated such that Moringa oleifera leaf meal was included at the levels of 0%, 10%, 20% and 30% for T1, T2, T3 and T4 respectively as presented in Table 1.

Blood Sample
Blood samples (5 ml) were drawn from each animal on the last day of the study. The rabbits were bled through the ear marginal vein. The samples were separated into two lots and used for biochemical and haematological studies. An initial 2.5 ml was collected from each sample in labelled sterile universal bottle containing 1.0 mg/ml ethyldiamine tetracetic acid and used for haematological analysis. Another 2.5 ml was collected over anti-coagulant free bottle. The blood was allowed to clot at room temperature and serum separated by centrifuging within three hours of collection. Serum biochemistry and haematological parameters were measured using Beckman Coulter Ac-T10 Laboratory Haematology Blood Analyzer and Bayer DCA 2000+ HbA1c analyzer, respectively. Mean cells haemoglobin (MCH), MCV and mean cell haemoglobin concentrations (MCHC) were calculated.

Analytical Procedure
All feeds and experimental materials were analyzed for proximate compositions using the method of [8].

Data Analysis
The results were analyzed using the Special Package for Social Sciences Window 17.0. Oneway analysis of variance (ANOVA) was employed to determine the means and standard error. Treatment means were compared using Duncan's new multiple range test.

RESULTS AND DISCUSSION
The proximate compositions of Moringa oleifera leaf meal and experimental diets are presented in Table 2 The heamatological indices of growing rabbit fed diet containing Moringa oleifera leaf meal is presented in Table 3. The packed cell volume (PCV), haemoglobin (Hb), mean cell haemoglobin concentration (MCHC) and white blood cell (WBC) were significantly (p<0.05) affected by the treatment diets while red blood cell (RBC), mean cell haemoglobin (MCH) and mean cell volume (MCV) were similar (P>0.05) among the treatment. PCV is a measure of the relating mass of blood and involved in the transport of oxygen and absorbed nutrients. However, the PCV (%) values for all the treatment groups fell within the normal physiological range of 30.0-50.0% reported by [14] for healthy rabbits, suggesting that MOLM were tolerated across the treatment groups. This agrees with the findings of [15] who reported that normal PCV values are indicators of adequate nutritional status of rabbits.
Haemoglobin functions in transporting oxygen to tissues of animal for oxidation of ingested food so as to release energy for the other body functions as well as transport carbon dioxide out of the body of animal [16]. The present study showed significant (P<0.05) difference among the treatments with T2 having the highest value and the lowest in T4 suggesting that Moringa oleifera leaf meal protein are of higher quality; a view corroborated by [17] that low level haemoglobin (Hb) of treatment could imply that dietary proteins were not of high quality. The MCHC values were significantly (P<0.05) affected with the rabbits fed treatment (T2) having the highest value (31.76 g/dl). The values recorded for all the treatment group however fell within the normal range (27-37) reported by [18]. The reported range of the MCHC in this study gave a clear indication of the absence of aneamia among the experimental animals.
White blood cells (WBC) function to fight infections, defend the body against invasion by foreign organisms and to produce or distribute antibodies in immune response. The range for WBC count obtained in this study ranged between 5.55 -10.66 (x10 6 /dl) and fell within the normal range for white blood cell (4.5 -11 (10g/l) reported by [18]. The WBC count was significantly (P<0.05) different among the treatments, with the highest in T4 and the lowest in the control. The increase in the level of WBC with the level of MOLM in the diet agreed with the reports of [19]. These results indicated that the animals were healthy because decrease in number of WBC below the normal range is an indication of allergic conditions, anaphylactic shock and certain parasitism, while elevated values (leucocytosis) indicates the existence of a recent infection, usually with bacteria.    Table 4 above shows the serum biochemistry of growing rabbits fed diet containing Moringa oleifera leaf meal. The treatment diets had a positive (p<0.05) influence among the treatments for the serum biochemical parameters except for creatinine that showed no significant (p<0.05) difference among the treatment groups. The result of total protein revealed that there were significant differences (P<0.05) among the treatment groups. T1 (Control) had the highest value (72.36 g/l) while T4 had the lowest value of (60.06 g/l). The values obtained in this study however fell within the normal range for healthy rabbits as reported by [20]; an indication of nutritional adequacy of the dietary proteins in this study.
The albumin and globulin also showed significant (P<0.05) difference among the experimental groups and fell within the normal physiological range for healthy rabbits. The range of values (31. .35/l) for albumin obtained in this present study fell within the normal range reported of (2.5 -4.5 gl dl -1 ) reported by [21] which is an indication of proper functioning of the liver in the rabbits. Abnormal serum albumin usually indicates an alteration of normal systemic protein utilization [22]. The globulin also fell within the normal range (1.5-3.3 g/dl) reported by [20] which is indicative of high immunity and good resistance to disease in the experimental animals. This perhaps highlights the ethnoveterinary properties of Moringa oleifera as reported by [4].
The cholesterol value in this study was significantly (P<0.05) affected by the treatment diets. There was a trend towards a reduction in the cholesterol value as the inclusion level of MOLM in the diet was increased. This observation agrees with the result of [23] who reported that juice extracted from Moringa leaves was found to be a hypocholestrolemic agent. This reduction in serum cholesterol level of rabbit fed the MOLM diet may suggest a general decline in lipid mobilization and maybe suggest that Moringa leaf meal diet were capable of reducing serum cholesterol, hence assisting in the reduction and deposition of cholesterol in the muscle; thus production of lean meat. This result also suggested that MOLM diets could be used to produce animal products with reduced cholesterol level. However, the values of cholesterol obtained in this study were found to be within the normal physiological range for rabbits (35.0-66.0mg/dl) reported by [24].
The urea values differed significantly (p<0.05) among the treatment groups. The higher level of urea in T1 animal could be as a result of increase in the activities of uric enzymes ornithine carbonoyle transferase and arginase. The low blood urea observed in the test animals are indication that the amino acids of M. oleifera are balanced, since high blood urea levels are associated with poor protein quality [25] or excess tissue catabolism associated with protein deficiency [26]. The result of this study is in agreement with the findings of [25] who observed that an amino acid imbalance would result in an increase in blood urea concentration. This perhaps highlights the high quality protein of M. oleifera as reported by [6].

CONCLUSION
From physiological point, blood profiles of rabbits in all treatment groups are within normal range for rabbit; an indication that the test ingredient enhanced feed quality and inadvertently the nutritional and health status of rabbits.

CONSENT
It is not applicable.

ETHICAL APPROVAL
This paper followed all the guidelines for the care and use of laboratory animal model of the