1
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified 
Cassava Peel Meal Based Diets
Peter-Damian Chukwunomso JIWUBA1*, Stanley Uzochukwu ILO2, Wisdom AMADURUONYE3, 
Nonye Lilian AZODO1, Chinenye UZOMA1
1Department of Animal Production Technology, Federal College of Agriculture, P.M.B.7008, Ishiagu, Ebonyi State, Nigeria
2Department of Animal Science, University of Nigeria, Nsukka, Enugu State, P.O.Box 3236 Nsukka Postal Code 410001, Nigeria
3Department of Animal Breeding and Physiology, Michael Okpara University of Agriculture, Umudike, PMB 7267 Umuahia, Nigeria
ABSTRACT
The effect of feeding pro-vitamin A cassava peel meal (PCPM) based diets to growing rabbits (n=48) for 61 days on their 
haematology and serum biochemical parameters was investigated. T1, T2, T3, and T4 diets were formulated with inclusion 
levels of 0, 15, 30, and 45%, respectively. In a completely randomized design, the rabbits were randomly allocated to four 
experimental groups of twelve animals each, with four rabbits constituting a replicate. On the last day of the study, blood 
samples were taken from each animal and analyzed for haematological and serum biochemical indices. The results of the 
proximate composition of experimental diets revealed that T2, T3, and T4 had high (p<0.05) ash values. T1 diet had higher 
(p<0.05) metabolizable energy (ME) in comparison with T3, and T4 diets. Red blood cells (RBC) and white blood cells 
(WBC) were improved (p<0.05) significantly in 15, 30, and 45% PCPM inclusions. T3 and T4 had better (p<0.05) packed 
cell volume (PCV) values, haemoglobin (Hb), mean cell haemoglobin (MCH), and mean cell haemoglobin concentration 
(MCHC) than T1 and T2. The treatment groups (T2, T3 and T4) had significantly higher (p<0.05) total protein, globulin, 
creatinine, total bilirubin, and aspartate amino transferase (AST). Cholesterol and urea levels were lowered significantly 
(p<0.05) in T3 and T4. All of the blood parameters were within the normal physiological range for clinically healthy rabbits, 
indicating that PCPM was beneficial to the rabbits' blood formation and health. T4 group had the best results and was 
recommended for enhanced rabbit production.
Key words: haematology, serum biochemistry, cassava peel, β- carotene, rabbits, biofortification
Agricultura 18: No 1-2: 1-8(2021)
https://doi.org/10.18690/agricultura.18.1-2.1-8.2021
*Correspondence to:
E-mail: jiwubapc@gmail.com or jiwubapc@yahoo.com                                                
INTRODUCTION
Rabbits are highly prolific livestock, play important roles 
in the provision of high quality animal protein to man and 
are extensively used as laboratory animals in the test for 
human diseases and drugs. Recently, rabbit production 
has gained popularity possibly not just due to its delicious 
high protein meat with low calories and fat contents and 
laboratory uses, but also because of its fast growth rate, short 
gestation interval, limited vital space, early maturity, ample 
nutritional spectrum, low capital intensity and no religious 
or social constraint against rabbit meat or rabbit production 
(Jiwuba et al., 2016a). Due to increasing popularity of rabbit 
production, it is therefore important to have a reliable set of 
normal haematological and biochemical reference values to 
aid in the diagnosis and prognosis of rabbit diseases in the 
tropics. Most of the normal reference values quoted in the 
literature were derived from rabbits reared under temperate 
environments. Hence, there is urgent need to develop 
2
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets
normal physiological haematological and serum biochemical 
reference values for rabbits reared under tropical conditions 
and fed tropical diets. 
Cassava peel, a by-product of cassava root processing, is 
one of such alternative tropical feedstuff. The National Root 
Crops Research Institute (NRCRI), Umudike, in partnership 
with the International Institute of Tropical Research Institute 
(IITA), Ibadan, Nigeria, has recently introduced pro-vitamin 
A cassava variants (Jiwuba and Ezenwaka, 2016). The pro-
vitamin A cassava was produced through traditional plant 
breeding or bioengineering (Sayre et al., 2011). The pro-
vitamin A cassava root is high in vitamin A and carotenoids 
and has a light yellow colouration when processed into 
different forms. The yellow colour observed in these varieties 
of cassava has led to higher demand and possible higher 
income to the farmers. Carotenoids, which abound in the 
new cassava pro-vitamin A, have extensive applications as 
antioxidants in dietary supplements (Jiwuba et al., 2016b) as 
blood precursor of vitamin A. The peels abound as a result of 
the root's great demand for a variety of human and industrial 
purposes. Also based on the fact that Nigeria still stand first 
in the world in cassava production and cassava-based foods 
being a staple food in the diet of Nigerians, this may have 
attributed to the gross availability of the peel. The peels are 
usually considered to contribute meaningful environmental 
problems when poorly discarded as waste. Therefore, 
incorporation into diets of rabbits will help to reduce 
environmental hazards as a result of poor waste management 
in the country. The objective of this study was to assess the 
effects of the diets in which maize was replaced by pro-
vitamin A cassava peel meal on the serum biochemical and 
haematological indices of growing rabbits. We assume that 
inclusion of 15 to 45 % of pro-vitamin A cassava peel meal 
will have a positive effect on blood profile of rabbit, due to its 
high pro-vitamin A content.
MATERIAL AND METHODS
The study was conducted at the rabbit section of Federal 
College of Agriculture, Ishiagu, Ivo Local Government Area, 
Ebonyi State. The College is located at latitude 5.560N and 
longitude 7.310E with an average annual rainfall of 1653 mm, 
a normal temperature of 28.50 °C, and a relative humidity of 
around 80%.
National Root Crops Research Institute, Umudike, Abia 
State, Nigeria provided the fresh pro-vitamin A cassava 
peels (TMS01368, TMS011412, and TMS1371). The peels 
were then milled and used to formulate pro-vitamin A 
cassava peel containing diets after being dried to around 10% 
moisture content. Table 1 shows four diets T1, T2, T3, and T4 
with inclusion levels of 0, 15, 30, and 45%, respectively.
The proximate compositions of experimental diets and 
test material (pro-vitamin A cassava peel meal) were 
determined using the method of AOAC (2000). Calculation 
of metabolizable energy (AAFCO, 1997) was employed:
ME = (3.5 × protein) + (8.5 × fat) + (3.5 × nitrogen free 
extract) × 10
At Michael Okpara University of Agriculture in Umudike, 
Abia State, Nigeria, 48 New Zealand white bucks were 
obtained. According to the approval and rules of the 
College's Animal Ethics Committee's research policy, the 
rabbits were stabilized for 21 days prior to the start of the 
study. Each animal was immunized against diseases that 
were common at the time. Prior to the experiment, they were 
dewormed with kepromec (Ivermectin) at a rate of 0.1 mL 
per rabbit subcutaneously and given an accaricide bath with 
Roys' Amitraz 20 at a rate of 1 mL per 2-litre water. Each 
rabbit was kept in a standard hutch that measured 120 by 
150 cm and was lifted 120 cm from the ground. The rabbits 
were randomized into four experimental treatments. In a 
completely randomized design, the four treatments were 
assigned to the four experimental diets. For 61 days, each 
animal was fed a treatment diet. Fresh drinking water was 
provided on a regular basis.
Blood samples (5 mL) were collected individually from 
the forty-eight rabbits through the marginal ear vein using 
sterilized syringe on the last day of the study. For the 
assessment of haematological parameters, approximately 
2.5 ml of blood from each rabbit was collected into vials 
containing ethylene diamine tetra-acetic acid (EDTA) 
as an anticoagulant. Another set was taken and placed 
in heparinized tubes for serum biochemistry analysis. 
The samples were divided into two groups and for tested 
haematological and biochemical indices. Beckman Coulter 
Ac-T10 Laboratory haematology Blood Analyzer and 
Bayer DCA 2000+ HbA1c analyzer were used to test serum 
biochemistry and haematological parameters, respectively. 
Accordingly, mean cell haemoglobin (MCH), mean cell 
volume (MCV), and mean cell haemoglobin concentrations 
(MCHC) were computed.
Dietary level (%)
Ingredients T1 T2 T3 T4
Maize 45.00 30.00 15.00 0.00
Pro-vitamin A cassava 
peel meal 0.00 15.00 30.00 45.00
Palm kernel meal 17.00 17.00 17.00 17.00
Soya bean meal 20.00 20.00 20.00 20.00
Wheat offal 12.00 12.00 12.00 12.00
Fish meal 2.00 2.00 2.00 2.00
Bone meal 2.00 2.00 2.00 2.00
Limestone 1.00 1.00 1.00 1.00
Methionine 0.25 0.25 0.25 0.25
Lysine 0.25 0.25 0.25 0.25
Salt 0.25 0.25 0.25 0.25
Vitamin premix 0.25 0.25 0.25 0.25
Total 100 100 100 100
Table 1: Composition of experimental diets
3
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets
The data was analyzed using the analysis of variance 
(ANOVA) method, as given by SAS (2008). The Duncan 
Multiple New Range Test was used to differentiate significant 
means.
RESULTS AND DISCUSSION 
Table 2 shows the chemical composition of the experimental 
diets. The dry matter (DM) values in this study varied from 
92.46 to 93.12% and were statistically similar (p>0.05), and 
were comparable to the range of 90.95 to 93.29 % provided 
by NRC (1997) for young rabbits. Though the incorporation 
of pro-vitamin A cassava peel meal had no effect (p>0.05) 
on the crude protein (CP), the values observed in this 
study were comparable to 16% and 18% CP requirements 
for growing rabbits stated by Omole and Onwudike (1982) 
and Abubakar et al. (2015), respectively. The CP range 
of 17.14 – 18.26% in the current study is higher than the 
15.97 – 16.00% obtained by Njidda and Isidahomen (2009) 
and lower than the 24.03 – 24.25% recorded by Jiwuba et 
al. (2016c) for growing rabbits, but comparable to 18.03 – 
19.92% recommended by NRC (1997) for growing rabbits. 
Nonetheless, the CP values observed in this study followed a 
certain pattern, decreasing linearly with increasing levels of 
PCPM, suggesting that the slight but steady decrease in CP 
values might be attributable to the PCPM. The crude fibre 
(CF) range of 14.36 – 16.07% was similar (p>0.05), and fell 
within the recommended range of 14 – 18% and 14 – 16% for 
young rabbits recommended by Mayer (1955) and Gidenne 
and Lebas (2002). In a previous study (Jiwuba, 2018), it was 
discovered that an adequate amount of dietary fibre lowers 
digestive difficulties, stimulates intestinal motility, and 
boosts rabbit growth. The study found a significant (p<0.05) 
increase in ash content as the PCPM level was increased, 
with T4 showing the highest numerical value and T1 having 
the least, implying that pro-vitamin A cassava peel meal is 
high in mineral. The treatment diets had no effect (p>0.05) 
on the ether extract (EE), however the reported 3.09 – 4.84% 
EE in this study is within the 2 – 5% crude fat requirement 
suggested for growing rabbits by Irlbeck (2001). The within 
recommended range for crude fat obtained in this study may 
be responsible for the glossy sleek hair of the experimental 
rabbits. The nitrogen free extract (NFE) was not significantly 
(p>0.05) influenced by the treatments. NFE can be used to 
assess non-fibrous carbohydrates such as sugars and starches. 
Agro waste, such as cassava peel, has been found to be high 
in fibre (Jiwuba and Jiwuba, 2020). In this study, T1 (control 
diet) had significantly (p<0.05) higher metabolizable energy 
levels than the other treatments. In this investigation, the 
observed range of 11.01 – 11.91 MJ/kg is in accordance with 
the recommended ranges of 10.00 – 11.72 MJ/kg and 10.46 
– 11.72 MJ/kg for growing rabbits by Aduku and Olukosi 
(1990) and Pond et al. (1995), respectively. 
Table 3 shows the chemical composition of pro-vitamin A 
cassava peel meal. According to chemical analyses, PCPM 
had 89.67% DM, 7.68% CP, 17.69% CF, 9.46% ash, 2.64% 
EE, 52.20% NFE, and 9.71MJ/kg metabolizable energy. This 
study's DM value of 89.67% is comparable with 89.90 and 
90.28% reported by Ajayi and Omotoso (2018), and Jiwuba et 
al. (2016b) for the same agricultural waste. The CP of 7.68% 
for cassava peel is fairly high for cassava peel, however, it 
could be due to the biofortication of the cassava cultivars. 
However, the CP of 9.23% noted by Jiwuba et al. (2016b) 
for the peel of the same cassava cultivars is higher than the 
value reported in the current study. The differences can be 
explained by the plant's age and soil fertility. The CF value 
for PCPM in this study was 17.69%, is higher than 12.93% 
reported by Jiwuba et al. (2016b) for the peel of the same 
cassava varieties. Hence, Jiwuba and Jiwuba (2020) noted 
that the crude protein and amino acids profile continues to 
decrease with age as crude fibre, hemicellulose, cellulose, 
and lignin increase with age. This study's high ash content of 
PCPM is more than 2.23% reported by Anaeto et al. (2013), 
but agreed well with 9.11% and 9.74 % reported by Ajayi and 
Omotoso (2015) and Jiwuba et al. (2016b) for cassava peel 
meals, respectively. The high NFE and energy levels in this 
present are consistent with previous studies Buitrago et al. 
(2002) and Olafadehan (2011).
Parameters (%) T1 T2 T3 T4 SEM p-value
Dry matter 92.46 92.91 92.78 93.12 1.51 0.857
Crude protein 18.26 18.04 17.38 17.14 0.49 0.293
Crude fibre 14.36 15.26 15.87 16.07 0.29 0.669
Ash 3.71b 5.11a 6.09a 6.25a 0.10 0.027
Ether extract 4.84 3.54 3.12 3.09 0.08 0.498
Nitrogen free extract 50.29 50.96 50.32 50.57 1.37 0.411
Metabolizable energy (MJ/kg) 11.91a 11.36ab 11.02b 11.01b 2.29 0.007
a-b means within the same row with different superscripts are significantly different (P<0.05); T1, T2, T3, T4 - 0, 15, 30 ,45% pro-vitamin A cassava peel meal, 
respectively; ME = (3.5 × protein) + (8.5 × fat) + (3.5 × nitrogen free extract) × 10
Table 2: Chemical composition of experimental diets 
Table 3: Chemical composition of pro-vitamin A cassava 
peel meal
Parameters (%) Provitamin Acassava peel meal
Dry matter 89.67
Crude protein 7.68
Crude fibre 17.69
Ash 9.46
Ether extract 2.64
Nitrogen free extract 52.20
Metabolizable energy (MJ/kg) 9.71
ME = (3.5 × protein) + (8.5 × fat) + (3.5 × nitrogen free extract) × 10
4
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets
Table 4 shows the haematological indices of growing rabbits 
fed pro-vitamin A cassava peel meal. The packed cell volume 
(PCV) did not follow any particular pattern, but it was 
significantly (p<0.05) higher in T3 and T4 than in T1 and T2. 
The haemoglobin (Hb), mean cell haemoglobin (MCH), and 
mean cell haemoglobin concentration (MCHC) all followed 
the same pattern as PCV, with T3 and T4 values higher (p<0.05) 
than T1 and T2. T1 had a lower RBC (p<0.05), in comparison 
to treatment groups (T2, T3, and T4). The white blood cells 
(WBC) differed significantly (p<0.05), with T3 and T4 having 
significantly higher values (p<0.05) than T1 and T2. The PCV 
range reported in this study was 37.87 – 45.55%, which was 
within the normal physiological ranges of 36 – 48%, 34 – 50%, 
and 31 – 50% for apparently healthy rabbits recommended 
by Aiello and Mays (1998), Hrapkiewicz and Medina (2007), 
and Hem et al. (2001), respectively. The rabbits fed the T3 
and T4 diets produced higher results, indicating a lack of 
anti-nutrients or a tolerable level of anti-nutrients, as well as 
increased blood supply. The Hb concentrations reported in 
this study for T1 and T4 were 9.89 – 15.06 g/l, respectively, and 
fell within Fudge's (1996) range of 9.4 – 17 g/dl for apparently 
healthy rabbits. The within normal physiological range may 
indicate that the quality of the diets in terms of protein 
were not compromised and hence supported higher oxygen 
carrying capacity of the blood among the animals. However, 
the higher Hb levels for rabbits fed T3 and T4 in comparison to 
T1 and T2 may be attributed to increased absorptive capacity 
occasioned by vitamin A, which is essential micronutrient 
in rabbit diets that enhances gene expression, development, 
growth and immune system. The RBC range of 4.55 – 7.11 × 
1012/L obtained in this investigation was within the ranges of 
4.0 – 7.2 × 1012/L and 4.5 – 8.5 ×1012/L reported for clinically 
healthy rabbits by Hillyer and Quesenberry (1997) and Bellier 
et al. (2005). The diets promoted improved transportation 
of haemoglobin via the red blood cells of the animals, as 
evidenced by greater RBC values. In addition, Hackbath et 
al. (1983) linked better RBC values with high-quality dietary 
protein and disease-free animals. The high CP and dietary 
fibre of the diets and the rabbits’ lack of health challenges 
demonstrated this during the experiment period. Higher RBC 
concentration, on the other hand, was linked by Jiwuba et al. 
(2020b) to better oxidation of digested feed and improved 
body functioning. The non-significant (p>0.05) influence of 
diets on mean cell volume reported in this study agrees with 
Jiwuba et al. (2020a) and Jiwuba et al. (2016a) earlier studies, 
but differs from Jiwuba et al. (2016c) and Onyekwere et al. 
(2018) findings for growing rabbits. The MCH value of 18.74 
– 25.66 pg found in this study complemented Jiwuba et al. 
(2016a) and Jiwuba et al. (2020b) for growing rabbits, which 
were 18.26 – 38.11 pg and 19.21 – 23.49 pg, respectively. A 
higher MCH content could indicate the lack of anemia and 
the bone marrow's ability to produce RBC with normal size 
and metabolic capacity. This also ruled out the possibility of 
anemia among the rabbits, even if the feeding was extended. 
The MCHC in this study (28.65 – 33.65%) fell within the 
normal range of 27 – 37% indicated by RAR (2009) for young 
rabbits. This also suggested that the animals were not anemic. 
The WBC levels in this study ranged from 6.46 – 12.33 × 
109/l for T1 and T4, respectively, and were within the ranges 
of 5 – 13 × 109/l and 4.0 – 13.0 × 109/l, suggested by Burke 
(1994) and Hem et al. (2001) respectively for healthy growing 
rabbits. This suggested that there was no microbial infection 
or parasite in the rabbit's blood, implying that including pro-
vitamin A cassava peel in the rabbit's diet had no negative 
impact on the animals' immunity or general health. This 
is in line with the findings of Moriguchi et al. (1996), who 
found that supplementing with beta-carotene increased the 
generation of lymphocytes, an indicator of immunological 
function and immune cell surveillance. However, the role 
of adequate dietary fibre in maintaining gut health, general 
health and general performance of the rabbits in this current 
study cannot be over emphasized. Earlier studies (Cheeke, 
1994; Jenkins, 1999) have shown that diets with lower dietary 
fibre below the minimum requirements can result in reduced 
gastro-intestinal motility, prolonged retention of digesta 
within the caecum, decreased formation of caecotrophs and 
a higher incidence of enteritis and diarrhea, which affects the 
general health and performance of the animals.
Table 5 shows the serum biochemical parameter of growing 
rabbits fed pro-vitamin A cassava peel meal in their diets. In 
comparison to the control group, total protein was significantly 
superior (p<0.05) in the treatment groups. Albumin, glucose 
and amino transferase (ALT) levels did not differ significantly 
(p>0.05) between treatments and did not follow a pattern 
with increasing or decreasing PCLM levels. The globulin 
level increased steadily (p<0.05) with increasing amount of 
PCLM in the meals, with T1 having the minimum value and 
T4 having the maximum. With increasing quantities of PCLM 
in the rabbits' diets. Serum urea values were significantly 
influenced (p<0.05) and declined linearly with T1 having 
the greatest value and T4 having the lowest value. Serum 
Parameters T1 T2 T3 T4 SEM p-value
Packed cell volume (%) 37.87b 39.73b 45.55a 43.29a 6.19 0.027
Haemoglobin (g/l) 9.89b 10.67b 14.33a 15.06a 3.34 0.003
Red blood cells (×1012/L) 4.55b 6.75a 7.11a 6.02a 1.23 0.021
Mean cell volume (fl) 65.98 66.85 67.99 66.87 11.83 0.764
Mean cell haemoglobin (pg) 18.74b 18.92b 25.66a 22.78a 4.62 0.023
Mean cell haemoglobin concentration (%) 28.65b 28.87b 32.09a 33.65a 5.78 0.000
White blood cells (×109/l) 6.46c 8.57b 11.11a 12.33a 1.68 0.007
a-c means within the same row with different superscripts are significantly different (P<0.05); ); T1, T2, T3, T4 - 0, 15, 30 ,45% pro-vitamin A cassava peel meal, 
respectively
Table 4: Haematological parameters of growing rabbits fed pro-vitamin A cassava peel meal in their diets
5
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets
creatinine values differed (p<0.05) significantly and increased 
linearly per additional levels of PCLM in the rabbits' diets, 
with T4 showing the highest value and T1 showing the least. 
Total bilirubin levels were significantly (p<0.05) affected, with 
T4 having the maximum value and T1 having the minimum. 
The rabbits' aspartate aminotransferase (AST) values were 
significantly influenced (p<0.05) and increased progressively 
per additional level of PCLM in the diets. The total protein 
levels in this study (60.45 – 71.81 g/l) were within the normal 
physiological ranges of 54 – 75 g/l, 50 – 75 g/l, and 53 – 75 
g/l, respectively, reported by Wolfensohn and Lloyd (1998), 
RAR (2009), and Suckow and Douglas (1997) for clinically 
healthy young rabbits. Considering that, protein synthesis is 
connected to the amount of dietary protein provided to the 
animal; this could signal that there is no muscle loss and that 
the rabbits survived without depleting their body reserves. 
This also revealed that rabbits on the treatment diets used 
dietary protein more efficiently than those in the control 
group, thus do, allowing for higher protein availability 
and utilization. The increased globulin values found in the 
treatment groups in this study indicate that the experimental 
animals have a higher level of immunity and resistance to 
diseases. This may have accentuated the ethno-veterinary 
qualities of vitamin A, as described by Lin et al. (2006), who 
stated that vitamin A is required for consolidation immunity 
through antibody formation, and that its deficiency would 
reduce immunological response and increase infection. 
Perhaps the values of 19.76 – 32.33 g/l obtained here were 
within the usual physiological ranges of 15 – 33 g/l and 19 – 
35 g/l for clinically healthy rabbits reported by BRV (2008) 
and Carpenter (2005), respectively, indicating that the diets 
supported the animals' immunity. Blood urea concentrations 
of 4.91 – 8.12 mmol/l in this investigation were within the 
ranges of 4.6 – 10.7 mmol/l and 6.1 – 8.4 mmol/l reported by 
BRV (2008) and Wolfensohn and Lloyd (1998) for apparently 
healthy growing rabbits, respectively. The reduced blood urea 
level recorded in T4 indicates that the diet's protein quality 
was improved, and so a high blood urea level is linked to 
poor protein quality Eggum (1970) or increased tissue 
catabolism complemented with protein insufficiency. This 
was in conformity with the findings of Jiwuba et al. (2016b) 
who fed pro-vitamin A cassava peel containing diets to West 
African Dwarf goats. Serum creatinine concentration of the 
rabbits followed a specific pattern, with the bucks receiving 
the treatment diets demonstrating greater values than those 
in the control group. The values obtained in this investigation 
(80.55 – 178.09 mmol/l) were within the normal physiological 
ranges of 44 – 230 mmol/l and 71 – 227 mmol/l, respectively, 
for apparently growing rabbits, as reported by BRV (2008) 
and Kaneko et al. (1997). This indicated that the rabbits' 
kidneys were not failing and that they survived at no cost to 
their body reserves, as proven by the fact that they did not lose 
weight during the experiment. The serum cholesterol levels 
(0.56 – 2.02 mmol/l) found in this study are within the range 
of 0.3 – 2.6 mmol/l reported for seemingly healthy young 
rabbits by Suckow and Douglas (1997). The PCLM caused a 
considerable reduction in serum cholesterol levels, according 
to the current findings. Jiwuba et al. (2016b), on the other 
hand, found no significant effect of PCLM on cholesterol 
concentration in WAD goats fed pro-vitamin A cassava peel 
meal in their diets. The drop in serum cholesterol levels in 
rabbits on PCLM diets could imply a reduction in overall 
fat mobilization and that PCLM diets were able to lower 
cholesterol, hence supporting the reduction and deposition 
of cholesterol in the muscles and improving the production 
of lean meat The fact that serum cholesterol levels were within 
normal physiological ranges in this investigation ruled out 
the possibility of fat malabsorption, heart disease, or liver 
dysfunction in the rabbits. Total bilirubin concentrations 
of 4.54 –8.21 mmol/l in this investigation were within the 
ranges of 3.4 – 8.6 mmol/l, 4.3 – 12.7 mmol/l, and 3.4 – 12 
mmol/l reported by Suckow and Douglas (1997), Wolfensohn 
and Lloyd (1998) and RAR (2009) for apparently healthy 
rabbits, respectively. Since total bilirubin is considered as an 
indicator of liver function, the fact that the diets were within 
normal clinical range in this study could signal that the diets 
were not harmful. The rabbits' AST concentrations followed 
a predictable pattern, with the rabbits on the treatment diets 
showing higher levels than the control group. The range of 
43.66 – 71.19 U/L found in this investigation was within the 
usual physiological ranges of 20 – 120 U/L, 14 – 113 U/L, and 
10 – 98 U/L for apparently growing rabbits as reported by 
RAR (2009), Suckow and Douglas (1997), and BRV (1998), 
respectively. This indicated that the diets were of good 
quality.
Table 5: Blood biochemical parameter of growing rabbits fed diets containing pro-vitamin A cassava peal meal
Dietary levels
Parameters T1 T2 T3 T4 SEM p-value
Total protein (g/l) 60.45c 63.87b 67.99ab 71.81a 1.54 0.005
Albumin (g/l) 40.69 40.22 39.88 38.67 0.34 0.284
Globulin (g/l) 19.76d 23.65c 28.11b 32.33a 0.27 0.001
Urea (mmol/L) 8.12a 7.45a 6.55ab 4.91b 0.05 0.009
Creatinine (mmol/l) 80.55d 101.76c 147.77b 178.09a 2.99 0.000
Cholesterol (mmol/l) 2.02a 1.44b 0.98c 0.56c 0.01 0.002
Total bilirubin (μmol/l) 4.54c 6.43b 6.31b 8.21a 0.08 0.024
Glucose (mmol/l) 4.76 4.86 4.71 4.80 0.13 0.165
AST (U/L) 43.66d 51.87c 60.56b 71.19a 0.62 0.000
ALT (U/L) 32.77 30.88 33.17 31.49 0.31 0.429
a-d means within the same row with different superscripts are significantly different (P<0.05); AST – Aspartate aminotransferase; ALT – Alanin aminotransferase; 
T1, T2, T3, T4 - 0, 15, 30 ,45% pro-vitamin A cassava peel meal, respectively
6
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets
CONCLUSION
In conclusion, this study showed that pro-vitamin A cassava 
peel meal supported haematological and serum biochemical 
indices of growing rabbits and therefore could be added in 
the diets of young rabbits up to 45% without any detrimental 
effect on the health status and erythropoiesis of the rabbits.
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Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets
8
Krvna slika pitovnih kuncev, krmljenih z obroki na osnovi
s provitaminom A obogatene lupine kasave
IZVLEČEK
V raziskavi so preučevali vpliv 61 dni trajajočega krmljenja pitovnih kuncev z obroki, ki so vključeval s provitaminom A 
obogateno lupino kasave (pro-ALK), na hematološke in serumske biokemične parametre. Obroki T1, T2, T3 in T4 so bili oblikovani 
tako, da so vključevali 0, 15, 30 in 45 % pro-ALK. V popolnoma slučajni poskusni zasnovi so bili kunci naključno razporejeni v 
štiri poskusne skupine po 12 živali, pri čemer so 4 kunci predstavljali ponovitev. Zadnji dan raziskave so vsaki živali odvzeli vzorce 
krvi, v katerih so analizirali hematološke in serumske biokemične kazalce. Rezultati okvirne sestave eksperimentalnih obrokov 
so pokazali, da so imele skupine T2, T3 in T4 višje (p<0,05) vsebnosti pepela kot obrok T1, obrok T1 pa je imel višjo vsebnost 
(p<0,05) presnovne energije v primerjavi z obrokoma T3 in T4. Rdeče in bele krvne celice so se znatno povečale (p<0,05) pri 
15, 30 in 45 % vključitvi pro-ALK. Obroka T3 in T4 sta imela večje vrednosti (p<0,05) za volumen celic, vsebnost hemoglobina, 
povprečni celični hemoglobin in povprečno koncentracijo celičnega hemoglobina kot obroka T1 in T2. Poskusne skupine (T2, 
T3 in T4) so  imele značilno višje vrednosti (p<0,05) skupnih beljakovin, globulina, kreatinina, skupnega bilirubina in aspartat 
aminotransferaze. Ravni holesterola in sečnine so se znatno znižale (p<0,05) pri obrokih T3 in T4. Vsi v krvi analizirani parametri 
so bili v normalnem fiziološkem območju za klinično zdrave kunce, kar kaže, da je bil pro-ALK koristen za tvorbo krvi in  zdravje 
kuncev. Najboljši rezultati so bili dobljeni pri obroku T4, zaradi česar je bil ta obrok priporočen za izboljšanje prireje kuncev.
Ključne besede: hematologija, serumska biokemija, lupina kasave, β-karoten, kunec, biofortifikacija
Blood Profile of Growing Rabbits Fed Pro-Vitamin A Fortified Cassava Peel Meal Based Diets