Asian Journal of Animal Sciences 9 (5): 217-224, 2015
ISSN 1819-1878 / DOI: 10.3923/ajas.2015.217.224
© 2015 Knowledgia Review, Malaysia
Comparative Response of Bitter Leaf (Vernonia amygdalina)
Infusion Administration on Performance, Haematology and Serum
Biochemistry of Broiler Chicks
1,2
Vivian U. Oleforuh-Okoleh, 1Solomon O. Olorunleke and 2Iyakutuye J. Nte
1
Department of Animal Science, Ebonyi State University, P.M.B. 053, Abakaliki, Ebonyi State, Nigeria
Department of Animal Science, Rivers State University of Science and Technology, Nkpolu-Oroworukwo,
P.M.B. 5080, Port Harcourt, Nigeria
2
Corresponding Author: Vivian U. Oleforuh-Okoleh, Department of Animal Science, Rivers State University of Science and
Technology, Nkpolu-Oroworukwo, P.M.B. 5080, Port Harcourt, Rivers State, Nigeria
ABSTRACT
Growing concern about antibiotic growth promoters in animal nutrition and its health
implication to consumers of poultry products has initiated efforts towards use of alternative growth
promoting agents especially medicinal plants. This study aimed at investigating the response of
broiler chicks administered bitter leaf (Vernonia amygdalina) infusion. Sixty day-old Marshal
broiler chicks were allotted in a Completely Randomized Design (CRD) to four treatment groups
identified as T1, T2, T3 and T4 consisting of three replicate with five birds per replicate. 50 g of
dried bitter leaf was infused for 12 h in 1 L of hot boiled water and given to the birds at T1 (0, 25
(T2), 50 (T3) and 75 mL LG1 (T4) of drinking water ad-libitum. Data collected on growth
performance traits revealed that feed intake was not influenced due to treatment, but final body
weight, weight gain and feed conversion ratio were increased. Carcass, drumstick, thigh and breast
weights and dressing percentage improved in treated groups. There was a reduction of
14.58-23.44% in abdominal fat in the treated group compared to T1. Although birds on T4 gave the
highest revenue, the best cost-benefit ratio was obtained from birds on T3. Except for packed cell
volume and white blood cell, the results showed no variations in other haematological parameters
measured. Cholesterol, low density lipoprotein and glucose concentration in the serum was reduced
in the treated group compared to the control. There was no influence on total protein and albumin:
globulin ratio in all treatment groups. T3 had the highest value for albumin. Administration of
bitter leaf infusion improved the growth performance, haematological and serum biochemical
indices of broiler chickens and can be applied in broiler nutrition.
Key words: Bitter leaf infusion, body weight, carcass weight, cost-benefit ratio, feed conversion
ratio, serum biochemical indices
INTRODUCTION
The feed industry is faced with a number of challenges, not only regarding the availability of
feed ingredients but also the ability to produce high quality products in a cost-effective manner
(Chauynarong et al., 2009). Khan et al. (2012) noted that various feed additives are used in poultry
to maximize net returns and carcass quality. The effects of any feed ingredient on the
haematological factors of the chicken are of immense assistance in deciding whether, or not, such
a feed ingredient will be used as poultry feedstuff (Mitruka and Rawnsley, 1997). Certain
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Asian J. Anim. Sci., 9 (5): 217-224, 2015
hematological factors such as packed cell volume, red blood cell, hemoglobin, etc., can be associated
with certain production traits and serve as means of assessing clinical and nutritional health status
of animals. For instance it has been established that high Packed Cell Volume (PCV) and high
hemoglobin content (Hb) are associated with high feed conversion ratio (Mitruka and Rawnsley,
1997), while high percentage white blood cells especially lymphocytes are associated with the
ability of the chicken to perform well under very stressful conditions.
Feed additives are ingredients added to poultry diets to enhance production efficiency, improve
health and reduce morbidity (FAO., 1998). A major feed additive which has been used for decades
in poultry production is the antibiotics. Bans on the use of antibiotics as feed additives have
accelerated and led to investigations of natural alternative feed additives in animal production
(Polat et al., 2011). Wang et al. (1998) reported that compared with synthetic antibiotics or
inorganic chemicals, these plant-derived products have proven to be natural, less toxic, residue free
and are thought to be ideal feed additives in food animal production. Rich store houses of medicinal
plants exist everywhere especially in Africa which offers a vast reservoir of plant that has been
categorized (Aluyi et al., 2003). Akinyemi et al. (2005) noted that the use of medicinal plants all
over the world predates the introduction of antibiotics and other modern drugs into the African
continent. Bitter leaf (Vernonia amygdalina) is a shrub or small tree and one of the edible
vegetables in Nigeria and other parts of African sub regions (Igbakin, 2009). It performs both
medicinal and nutritive functions (Adaramoye et al., 2008). WHO (1996) describes a medicinal plant
as any plant in which one or more of its organ contains substances that can be used for therapeutic
purposes or which are precursors for the synthesis of useful drugs. It is popularly called bitter leaf
because of its abundant bitter principles (Ekpo et al., 2007). The leaves contain a considerable
amount of anti-nutritive factors like high level of tannic acid and saponin. Proximate composition
of Vernonia amygdalina Leaf Meal (VALM) shows a chemical composition of 527.83 ME kcal kgG1,
86.40% DM, 21.50% CP, 13.10% CF, 6.80% EE, 11.05% Ash and the result on mineral composition
indicate that V. amygdalina has 3.85% Ca, 0.40% Mg, 0.03% P, 0.006% Fe, 0.33% K and 0.05% Na
(Owen et al., 2009). It is one of the natural feed additives which can be of great productive and
health importance in the broiler industry.
The present study was designed to evaluate the efficacy of different levels of bitter leaf aqueous
extract on growth performance, economics of production, carcass quality and blood parameters of
broiler chicks.
MATERIALS AND METHODS
Location of study: The study was carried out at the Poultry Experimental Unit of the Department
of Animal Science, Ebonyi State University, Abakaliki, Nigeria. Abakaliki is located within the
Southern Guinea Sanannah Zone at between latitude 06o 4’N and longitude 08o 65’E with a day
length range of 12-14 h all year round. It has an annual mean rainfall range of between
1500-2250 mm with mean daily temperature ranges of 27oC and relative humidity of 85%.
Preparation of infusion: Fresh leaves of bitter leaf were bought from the local market in
Abakaliki, Nigeria. These were washed thoroughly without squeezing with clean tap water to
remove dirt (sand and dust). Washed leaves were air-dried at room temperature for two weeks until
they became brittle. The dried leaves were pulverized using a hammer mill and stored in an
air-tight plastic container. Fifty gram of pulverized leaves was infused in 1 L of hot boiled water
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Asian J. Anim. Sci., 9 (5): 217-224, 2015
Table 1: Proximate composition of feed
Nutrients
Crude protein
Fat/oil
Crude fibre
Calcium
Available phosphorus
Lysine
Methionine
Salt
ME (kcal kgG1)
Starter
22.00
6.00
5.00
1.00
0.45
1.20
0.55
0.30
2900
Finisher
18.00
6.00
5.00
1.00
0.40
0.85
0.35
0.30
2900
for 12 h (overnight). The infusion was thereafter, filtered using a filter paper and the filtrate
administered to the chicks according to the treatment dose. Infusion was prepared daily.
Experimental animals, design and management: This study which lasted for 54 days was
performed with sixty day-old straight-run Marshal strain broiler chicks procured from Obasanjo
Farm, Ota, Ogun state, Nigeria. It was initiated by raising communally the day-old chicks for seven
days. On the 8th day, the birds were randomly allotted into four treatments designated T1- 0,
T2- 25, T3- 50 and T4- 75 mLG1 of bitter leaf infusion per litre of drinking water. Each of the
treatment was replicated three times, with five birds per replicate in a Completely Randomized
Design (CRD). Water was made available to the chicks ad libitum. All chicks were fed ad libitum
with same commercial diet. Proximate composition of the feed as given by the feed manufacturer
is presented in Table 1.
Data on growth performance of broiler chicks were obtained by records from the daily feed
intake and weekly body weight. These were used to calculate the feed conversion ratio
(feed consumed divided by weight gain) at the end of the experiment. At the end of the experiment,
one bird was selected from each replicate, i.e., three birds per treatment. The selected birds were
fasted for 12 h and weighed prior to slaughtering. The carcass weight, weight of prime cuts
(drumstick, thigh, breast, back and giblets) and abdominal fat weight were obtained. The weights
of the cuts and abdominal fat were expressed as relative percentage weight of the carcass. A costbenefit analysis was done to evaluate the economic efficiency of administering bitter leaf infusion
to broiler chicks. Data obtained from the cost/kg feed consumed/bird, cost of production and revenue
were estimated and applied in the cost-benefit analysis.
Data on blood parameters were also obtained at the end of the feeding trial. Three birds each
were randomly selected from each replicate group and 2 mL of blood collected from the wing vein
with sterile needle into well labeled sterilized bottles that contained EDTA as anticoagulant. These
were used to determine the Packed Cell Volume (PCV), Red Blood Cell (RBC), White Blood Cell
(WBC) and the hemoglobin (Hb) count according to Dein (1984). Another 2 mL of blood was
collected from the birds without anticoagulant into a vacutainer to determine the following serum
biochemical indices (total protein, albumin, glucose, globulin, cholesterol, LDL and HDL level in
the blood).
Data were analyzed statistically using one-way analysis of variance (ANOVA) and significant
means were compared using Duncan’s New Multiple Range Test at 5% significance level. The
analysis was done using SPSS 13 for windows. The experimental model applied was:
Xij = µ+Ti+Eij
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Asian J. Anim. Sci., 9 (5): 217-224, 2015
Where:
Xij = Any observation made in the experiment
µ = Observed mean
Ti = Effect of dosage (i = 25, 50 and 75 mL)
Eij = Residual error
RESULTS AND DISCUSSION
The effect of oral administration of bitter leaf aqueous extract on the performance of broiler
chickens is presented in Table 2. The result indicates that no difference (p>0.05) was observed in
daily feed intake among the four treatment groups. However, there were significant variations
(p<0.05) in the final body weight, daily weight gain and feed conversion ratio-ranging between
268.72-413.57, 5.07-7.88 and 0.35 0.30 g, respectively-between T1 and the other treatments
(T2, T3 and T4). However, birds on T4 had the best performance, numerically, when compared to
the other treated groups. The result of the present study is in line with the findings of
Tangka (2003) and Durunna et al. (2011) who reported improved growth performance of animals
fed bitter leaf. The improvement observed in the improved weight gain is correlated with the lower
FCR observed in the treated group. The lower the FCR the higher it is for the birds to convert feed
consumed to meat. Olobatoke and Oloniruha (2009) reported that inclusion of bitter leaf powder
in cockerels feed significantly improved FCR.
Adaramoye et al. (2008) opined that the improvement observed could be associated with the
beneficial effect of bitter leaf in enhancing the gastro intestinal enzyme thereby improving
digestion and assimilation of nutrients. Huffman et al. (1996) also reported that bitter leaf
enhanced gastro intestinal enzymes (chymotrypsin) production which may improve not only the
utilization of feed but could aid in the digestion of sporozites and other intestinal parasites that
Table 2: Effects of oral administration of bitter leaf aqueous extract on performance of broiler chickens
Parameters
T1 (0 mL)
T2 (25 mL)
T3 (50 mL)
T4 (75 mL)
±SEM
Growth performance traits
Initial body weight (g)
170.67
165.33
166.67
158.67
10.45
2235.15a
2352.30a
2380.00a
120.12
Final body weight (g)
1966.43b
38.33a
40.48a
41.14a
1.94
Daily weight gain (g)
33.26b
Daily feed intake (g)
94.26
97.20
100.54
104.08
11.60
Feed conversion ratio
2.84b
2.54a
2.49a
2.53a
0.10
Economic analysis
577.39bc
597.18ab
618.23a
13.86
Cost/kg feed consumed/bird
559.91c
278.96a
273.23a
279.32a
14.52
Cost/kg live weight gain
311.80b
Cost of prod.(x)**
822.91c
840.39bc
860.18ab
881.23a
19.97
1676.36b
1764.23a
1785.00a
26.28
Revenue (x)***
1474.82c
Cost-benefit ratio
1.26c
1.01b
0.95a
0.98ab
0.02
Carcass quality
Live weight before slaughter (g)
1633.33
1900.00
2216.67
2166.07
298.37
Carcass weight (g)
1233.33b
1516.67ab
1777.33a
1816.67a
204.18
Dressing percentage
75.92c
79.80b
80.02b
83.87a
1.16
3.60c
4.01b
3.98b
0.06
Abdominal fat*
4.70a
Drumstick*
11.87c
12.26b
12.32b
13.31a
0.14
Thigh*
14.35c
17.41a
17.20a
15.12a
0.28
Wing*
10.68
11.85
10.53
10.81
0.92
Breast*
22.81a
21.93a
17.20b
23.62a
1.29
Giblets*y
11.03
11.41
11.42
11.01
1.02
ab
Means on the same row followed by different superscript are significantly different (p<0.05); yGiblets-heart, liver, gizzard and neck,
*Weight of cuts/organs expressed as % of carcass weight, **Cost of production = Cost of feed+cost of medication+cost of day old chick and
***
Revenue based on x750 kgG1 live weight
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Asian J. Anim. Sci., 9 (5): 217-224, 2015
could cause decreased utilization of feed. Mohammed and Zakariyau (2012), contrarily, observed
that inclusion of bitter leaf as a feed additive did not significantly improve weight gain and FCR
in broilers.
Table 2 also reveals that the cost/kg feed consumed/bird as well as cost of production increased
with increase in the quantity of bitter leaf extract in the drinking water. However, the cost of
feed/kg live weight gain was least for birds on T3 while those on control had the highest
cost (a difference of up to N38.57). Although T4 gave the highest revenue, the best revenue,
numerically, was obtained from birds on T3 (a margin of N0.28 between T3 and T4). This, further,
translated to a better cost-benefit ratio. The present result is in consonance with the findings of
Kyvsgard (2002) which noted that broilers fed bitter leaf performed better in terms of cost of feed
per kg gain than those on control.
Though no variations (p>0.05) existed in the live weight of birds in all treatments, there were
significant variations (p<0.05) between the treatments groups in carcass weight and dressing
percentage, particularly, between T1 and other treatments (Table 2). Birds on T4 had a better
performance. Their carcass weight was 32.11% heavier than those on T1 and their dressing
percentage 9.48, 4.85 and 4.59% better than those on T1, T2 and T3 respectively. There was a
reduction (p<0.05) of 14.58-23.44% in abdominal fat in the treated group compared to T1.
Isika et al. (2012) observed that dressed weight, eviscerated weight and abdominal fats were higher
(p<0.05) in the control diet than in the test diet when 0.25% bitter leaf, ginger and a mixture of the
two herbs were included the diets of broiler chicks. Javed et al. (2009) observed a significant
increase in dressing percentage in broiler chicks in response to an aqueous extract of plant mixture.
Oleforuh-Okoleh et al. (2014) demonstrated that abdominal fat was significantly reduced in broiler
chicks treated with ground ginger and garlic. It is supposed that the improvement in the FCR
resulted in improved muscle development hence the observation made in the treated groups.
Furthermore, this could also be attributed to the hypolipidaemic effect of bitter leaf which ensured
the development of leaner meat.
Table 3 presents the blood parameters of the experimental birds. The hemoglobin
concentration (Hb) and Red Blood Cell (RBC) of the experimental birds were not statistical
different (p>0.05), though they increased numerically as levels of aqueous extracts of bitter leaf
increased.
Table 3: Blood parameters of broiler chicks administered aqueous extracts of bitter leaf
Parameters
T1 (0 mL)
T2 (25 mL)
T3 (50 mL)
Haematological
32.00a
30.66a
PCV (%)
24.33b
Hb (g dLG1)
9.74
10.64
10.22
RBC (x106/mm3)
3.99
4.23
4.35
473.00c
522.00a
493.33b
WBC (x103/mm3)
MCV (fl)
60.98
75.65
70.48
MCHC (%)
33.33
33.25
40.03
MCH (pg)
24.89
25.13
22.39
Serum biochemistry
Cholesterol (mg dLG1)
132.12a
113.99b
86.23c
1
a
b
LDL (mg dLG )
137.91
112.14
79.91c
33.51c
69.60a
63.16a
HDL (mg dLG1)
1
Total protein (g LG )
40.33
42.00
43.66
A/G ratio
1.02
1.09
1.15
20.33b
21.94ab
23.33a
Albumin (g LG1)
Glucose (FBS) (mg dLG1)
138.60a
131.00b
129.20b
a,b,c
Means on the same row with different superscripts are significantly different (p<0.05)
221
T4 (75 mL)
±SEM
31.33a
10.44
4.11
498.66b
76.22
33.32
26.19
1.12
0.74
1.72
6.14
3.88
8.06
1.36
112.21b
103.89b
47.69b
43.06
1.09
22.42a
127.20b
7.34
2.47
3.86
1.96
0.33
0.94
2.93
Asian J. Anim. Sci., 9 (5): 217-224, 2015
Osho et al. (2014) demonstrated that oral administration of bitter leaf extract on broiler
chickens did not have a significant effect on the Hb and RBC in treated birds. The Packed Cell
Volume (PCV) and total White Blood Cell (WBC) count of the birds were significantly increased in
the treated group. Owen and Amakiri (2011) made similar observation, where with the exception
of White Blood Cell (WBC), all other hematological indices measured were influenced by increasing
levels of Vernonia amygdalina leaf meal. Aregheore et al. (1998) suggested that the presence of
some phytochemicals in bitter leaf extract induces the animal to respond as if it has infection.
Thus increase in WBC could also be attributed to the presence of anti-nutritional compounds in
Vernonia amygdalina. The PCV values were within the normal range of 25-45%.
Results in Table 3 also reveals that administration of bitter leaf extract significantly (p<0.05)
reduced serum cholesterol in the blood plasma. The LDL of the birds on T2 were similar (p>0.05)
to T4, but significantly higher than (p<0.05) those on T3 and lower than those on T1. Nwanjo and
Nwokoro (2004) in their study on effects of aqueous extract of Vernonia amygdalina on rats
concluded that the plant possesses anti-oxidant property. Ojiako and Nwanjo (2006) documented
that administration of bitter leaf significantly attenuated the LDL cholesterol level of
streptozotocin diabetic rats. Owen et al. (2011a) also reported serum cholesterol and LDL lowering
potentials of bitter leaf meal. Increased activity of the enzyme catalase involved in esterification
of cholesterol in the plasma could have influenced the decrease in serum cholesterol in the bitter
leaf extract administered birds. Birds on bitter leaf aqueous extract had better HDL values
compared to those on control. This indicated that the tendency of having high serum lipid can be
prevented by supplementation of natural additives.
The fasting blood glucose of broilers on bitter leaf aqueous extract was significantly reduced
with increasing level of bitter leaf in the drinking water. A reduction of 5.5-8.23% of glucose level
between the control and the treated group was observed. The finding affirms the work of Osinubi
(2006) and Owen et al. (2011b) which suggested that Vernonia amygdalina has hypoglycemic effect.
Akah and Okafor (1992) reported that bitter leaf possess both hypoglycemic properties. Two
mechanisms have been adduced for the hypoglycemic effect observed in the administration of bitter
leaf. The works of Atangwho et al. (2007) on the effect of V. amygdalina leaf on kidney function of
diabetic rats depicts that one of the mechanisms is the targeting of insulin synthesis/production
from the beta-cells of the islet of Langerhans and the second on peripheral carbohydrate
mechanism.
Total protein and albumin tests are usually used to evaluate the health status of animals. These
tests are often used in diagnosing diseases and in monitoring changes in health status of farm
animals. The total protein is a composite of the albumin and globulin content in the blood and is
a reflection of the nutritional status of the birds. Low levels of albumin indicate incidence of disease
related to the liver or kidney. It could also be associated with presence of infection. Total protein
of the birds on T3 was significantly higher than those of other treatments. Similar trend was
observed in the albumin. This finding concurs with earlier report by Owen et al. (2011b).
The inclusion of bitter leaf aqueous extract in the diets of broiler chickens had no adverse effect
on the performance traits as well as economic production parameters evaluated. Furthermore,
administration of the extract reduced the total cholesterol, LDL and glucose in the blood plasma.
The best administration level with respect to cumulative effect on all parameters investigated was
50 mL LG1 of drinking water. This implies that the administration of this natural herb at this level
of inclusion could be important in improving the productivity and health status of broiler chicks.
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ACKNOWLEDGMENTS
This experiment was financially supported by Obi Lynda, C. and Ohanu Onyekachi O. of
Department of Animal Science, Ebonyi State University, Abakaliki.
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