Nigerian Journal of Agriculture, Food and Environment. 11(2):53-58
Ndelekwute et al., 2015
Published June, 2015
EFFECT OF LIME (Citrus auentifolia) JUICE ON MEAT YIELD AND
PROFITABILITY OF BROILERS
Ndelekwute1, E. K., Okereke2, C. O., Essien1, E. B. and Udorok1, U. E.
ABSTRACT
1Department
2Livestock
of Animal Science, University of Uyo, Uyo, Nigeria.
Unit, National Root Crops Research Institute. Umudike, Abia State, Nigeria
The experiment was conducted to determine the effect of lime juice on carcass yield, meat quality, internal organs and
economic benefit of broiler chickens. 150 day old broilers of Anak strain were used in a 5x3 randomized experiment with each
units of ten birds serving as replicates within each treatment. Five diet treatments containing 0.00, 10, 15, 20 and 25mls/kg of
lime juice respectively. The experiment lasted for 8 weeks. Feed and water were offered ad libitum. Results showed that the
lime juice had no significant effect on carcass yield, nutritive value and meat pH but significantly (P<0.05) increased the size
of kidney, gall bladder, revenue and gross margin and bile volume. The size of the small intestine was reduced significantly
(P<0.05) reduced while 20 and 25mls of juice reduced abdominal fat significantly (P<0.05). Therefore, 20mls/kg feed of lime
juice positively influenced the economic benefit of broilers without detrimental effect on the carcass and could be
recommended for use by broiler farmers.
Keywords: broiler, carcass, benefit, organs, meat.
INTRODUCTION
Supplementing animal feeds with feed additive based growth promoters has been a common practice for many
years (Wegener et al., 1999). It helps growing animals to effectively digest their feed, derive maximum benefit
from it and thereby allowing them to grow strong and healthy. A current challenge in the poultry production is to
exploit the use of specific dietary supplements to boost the intrinsic potential of poultry birds to perform better.
One of the nutritional strategies to enhancing the rapid growth of monogastric animals had been the addition of
feed additives such as antibiotics (Windisch et al., 2007). Although antibiotics possess beneficial effects, their use
as growth promoters in the poultry industry has been intensively controversial because of the development of
bacterial resistance and potential negative consequences on human health.
According to World Health Organization (WHO), resistance to antibiotics is the ability of the bacterial population
to survive the inhibitory or lethal effect of antimicrobial agent resulting from the previous exposure to sub
therapeutic level of the antimicrobial agent (Akpodiette et al., 2000.). The dangers posed by the development of
resistance in poultry and human beings have been documented. Ricke, (2003) showed that resistant bacteria can
be transferred from poultry products to human population through consumption or handling of poultry meat
contaminated with the resistant pathogen. There is an increasing interest in utilization of growth promoters of
natural origin (Grela and Klebamik, 2007). This has resulted to the use of organic acids, spices and essential oils
(Ndelekwute et al., 2013).The supplementation of organic acids in the diets of broilers enhanced nutrient
utilization, growth and feed efficiency (Doyle, 2001).
Organic acids such as citric, ascorbic, acetic, and butyric and formic acids occur naturally such as in fruits and
ants. However, available information on organic acids was on synthetic types which most farmers may not have
access to. The next alternative is to use natural sources which could be accessed easily. Lime a citrus spp which
abounds in tropical ecosystem is a rich source of citric and ascorbic acids (Vandercook, 1977; Penniston et al.,
2008); NFH, 2013). Therefore, the objective of this study was to determine the effect of natural organic acids
contained in lime juice on carcass, internal organs and the economic benefit.
MATERIALS AND METHODS
Experimental site
The experiment was conducted at the Poultry unit of the University of Uyo Teaching and Research Farm. Uyo is
situated at between latitude 4 ̊ 50' and 5 ̊ 07' N and longitude 7 ̊ 45' and 8 ̊ 05' E in the rainforest zone with annual
rainfall of 800mm. The experiment was conducted during rainy season with temperature range of 28 - 32°C
throughout the duration of the experiment.
Processing of natural source of organic acids
The lime fruits were washed with clean water and cut into two halves with a sharp knife. The juice was expelled
manually by squeezing and juice containing the seeds was passed through a filter material to remove the seeds.
After which the citric and ascorbic acids content and the pH were determined according to Holden et al. (2005),
Novella (2014) and Helmenstine (2014).
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Nigerian Journal of Agriculture, Food and Environment. 11(2):53-58
Ndelekwute et al., 2015
Published June, 2015
Experimental design and diet
Completely randomized design (CRD) was employed. The experiment was conducted with 150 day old unsexed
broiler chicks of Anak strain. The chicks were randomly divided into five treatment groups (T1, T2, T3, T4 and
T5) each having 30 chicks. Each treatment was replicated three times of 10 chicks each. T1 was the control
containing no lime juice. The other treatment groups contained respectively 10, 15, 20 and 25 ml of lime juice per
kg feed. The experiment started from the first week. The diets were formulated as recommended by NRC (1994)
as shown in Tables 1 and 2. The proximate analysis was done according to AOAC (2000).
Table 1: Ingredient and nutrient composition of experimental starter diet
Ingredients (%)
Maize
Soybean meal
Fish meal
Palm kernel cake
Wheat offal
Bone meal
Lime juice
Salt
Lysine
Methionine
Premix*
Total
Nutrient Composition (%)
Crude Protein
Crude Fibre
Ether Extract
Total Ash
Calcium
Phosphorus
Lysine
Methionine
Energy (KcalME/kg )
T1
53.00
30.00
3.00
6.20
4.00
3.00
0.00
0.25
0.20
0.10
0.25
100
T2
53.00
30.00
3.00
6.20
3.00
3.00
1.00
0.25
0.20
0.10
0.25
100
T3
53.00
30.00
3.00
6.20
2.50
3.00
1.50
0.25
0.20
0.10
0.25
100
T4
53.00
30.00
3.00
5.20
2.00
3.00
2.00
0.25
0.20
0.10
0.25
100
T5
53.00
30.00
3.00
5.20
1.50
3.00
2.50
0.25
0.20
0.10
0.25
100
22.35
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2875
22.18
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2858
22.10
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2850
22.00
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2841
21.94
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2833
*Starter Premix supplied per kg diet: vitamin A 15,000 I.U, vitamin D3 13000 iu, thiamin 2mg, Riboflavin 6mg, pyridoxine 4mg, Niacin
40mg, cobalamine 0.05g, Biotin 0.08mg, choline chloride 0.05g, Manganese 0.096g, Zinc 0.06g, Iron 0.024g, Copper 0.006g, Iodine 0.014g,
Selenium 0.24mg, Cobalt 0.024mg and Antioxidant 0.125g. CON = control, AA = acetic acid, BA = butyric acid, CA = citric acid, FA =
formic acid
Management of experimental birds
Upon arrival, the birds were weighed and the initial weight was recorded. To cushion the effect of stress, they
were given glucose through drinking water. The birds were brooded for 3 weeks. On the second day vitamin,
minerals and antibiotic were added to their drinking water for one week. The birds were exposed to 24hrs lighting
schedule throughout the brooding period. Adequate sanitary measures were taken. The birds were adequately
given medications as prophylactic measures against bacteria mycoplasma and cocccidial infection. Newcastle and
Gumboro disease vaccines were administered. The birds were transferred to rearing house at the end of the third
week. Feed and water were given ad libitum throughout the experiment.
Carcass and internal organ analysis
Carcass analysis was performed based on the procedure outlines by Scott et al. (1969). At the end of the feeding
experiment, 15 birds, one from each replicate of a treatment were used for carcass analysis. The birds were fasted
for 18 hours to clear the gut. They were slaughtered by severing the neck with sharp knife and both the trachea
and oesophagus were cut. Hot water was used to remove the feathers by immersing in hot water for 30 seconds
according to Oluyemi and Roberts (2000). The loosed feathers were immediately plucked by hand.
The legs, head and neck were cut and the crop gently removed. The abdomen was cut open and holding the
gizzard the viscera was pulled out and the abdominal fat was removed. The dressed bird was then cut into parts
(breast, thigh, drumstick back and wing). Weight of the dressed parts, abdominal fat and internal organs were
determined. Dress carcass weight, internal organs and abdominal fat were expressed as percentage live weight
while weights of different cut carcass parts were expressed as percentage of dressed carcass weight according to
Ndelekwute et al. (2013). The data were transformed using Arc Sin according to Preston (1996) as reported by
Ndelekwute et al. (2013).
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Nigerian Journal of Agriculture, Food and Environment. 11(2):53-58
Ndelekwute et al., 2015
Published June, 2015
Determination of nutritive value of the meat
The meat from the breast, thigh and drumstick were used to determine the crude protein, ether extract, crude fibre
and ash content. Skin of each mentioned cut parts was gently removed and 20g of meat from each was removed.
They were pulled together and homogenized. Proximate Analysis was carried out according to AOAC (2000).
The meat pH was determined by first mixing 10g of the homogenized meat with 10ml deionised water. Thereafter
an electrode of pH meter (Havana Micro computer pH meter, model H18424, made in Romania) was dipped into
the mixture and reading taken.
Table 2: Ingredient and nutrient composition of experimental finisher diet
Ingredients (%)
Maize
Soybean meal
Palm kernel cake
Wheat offal
Bone meal
Lime juice
Salt
Lysine
Methionine
Premix
Total
Nutrient Composition (%)
Crude Protein
Crude Fibre
Ether Extract
Total Ash
Calcium
Phosphorus
Lysine
Methionine
Energy (KcalME kg-1 diet)
T1
54.00
27.00
9.30
4.00
3.00
0.00
0.25
0.10
0.10
0.25
100
T2
53.40
27.00
9.30
5.00
3.00
1.00
0.25
0.10
0.10
0.25
100
T3
54.00
27.00
9.30
4.50.
3.00
1.50
0.25
0.10
0.10
0.25
100
T4
54.00
27.00
9.30
4.00
3.00
2.00
0.25
0.10
0.10
0.25
100
T5
54.00
27.00
9.30
3.50
3.00
2.50
0.25
0.10
0.10
0.25
100
20.45
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2901
20.28
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2884
20.19
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2876
20,.11
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2867
20.06
4.13
4.10
8.00
1.08
1.01
1.10
0.50
2859
*.Finisher Premix supplied per kg diet vitamin 10, 0001.u., vitamin D3 12,0001.u. Vitamin E 201.U., Vitamin K 2.5mg, thiamine 2.0mg,
Riboflavin 3.0mg, pyridoxine 4.0mg, Niacin 20mg, cobalamin 0.05mg, pantthemic acid 5.0mg, Folic acid 0.5mg, Biotin 0.08mg, choline
chloride 0.2mg, Manganese 0.006g, Zinc 0.03g, Copper 0.006g, Iodine 0.0014g, Selenium 0.24g, cobalt 0.25g and antioxidant 0.125g
Economic benefit analysis
Economic analysis was carried out to determine the economic implications of adding lime juice to broiler diet.
Parameters used to judge this were cost per kg feed, feed cost per bird, feed per weight gain, revenue per bird and
gross margin per bird which were calculated as follows.
Cost per kg feed =
Summation of price per kg of feed ingredients x their
Proportion in the feed formula ÷ 100
Feed cost per bird=
Cost per kg feed x quantity of feed consumed.
Total feed cost
=
feed cost per bird of starter phase + feed cost per bird of finisher phase
Feed cost per weight gain =
Cost per kg feed x feed: gain ratio.
Revenue per bird
=
Price per kg live bird x Final live weight
Goss margin
=
Revenue per bird – feed cost per bird
Statistical analysis
All data generated were subjected to analysis of variance and means that were significantly difference were
separated using Duncan New Multiple Range Test according to Steel and Torrie (1980).
RESULTS AND DISCUSSION
Organic acid content and pH of lime juice
The lime juice contained 1.60% citric and 1.20% ascorbic acids with pH of 3.5. This is a clear indication that the
lime juice was acidic confirming the report of Novella (2014). However, the citric acid content was not in line
with Pennistine et al. (2014) who reported 4.8% may be as a result of location and seasonal variation.
Carcass yield and internal organs
The effect of lime juice on carcass quality (Table 3) shows that there were no differences (P>0.05). This implies
that the lime juice was not deleterious on the carcass and can be used to produce broiler chickens. Abdominal fat
was significantly (P<0.050 reduced by 20 and 25mls of lime juice. This is in accordance to the report that lime
juice reduced body fat and was used to trim weight in human (Liu et al., 2012).
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Nigerian Journal of Agriculture, Food and Environment. 11(2):53-58
Ndelekwute et al., 2015
Published June, 2015
Table 3: Effect of natural organic acids on carcass yield of broilers
T1(0ml kg-1)
67.67
37.33
15.33
14.33
20.33
12.33
1.55a
Parameter
Dressed (%)
Breast (%)
Thigh (%)
Drumstick (%)
Back (%)
Wing (%)
Abdominal fat (%)
T2(10ml kg-1)
65.00
35.67
16.67
16.00
19.67
12.33
1.45a
T3(15ml kg-1)
66.67
37.33
15.33
14.33
21.67
11.60
1.40a
T4(20ml kg-1)
64.67
37.67
16.33
14.67
19.67
11.70
0.75b
T5(25ml kg-1)
66.00
36.33
16.33
14.00
21.67
12.00
0.60b
SEM
5.04
4.12
3.05
3.11
4.25
2.86
0.31
ab Means along the same row with different superscripts are significantly (P<0.05) different.
Effect of citric acid on the internal organ of broilers is shown in Table 4. It indicates that only the kidney, gall
bladder, bile volume and small intestine were significantly (P<0.05) different. The kidney, gall bladder, bile
volume were heavier in the treated groups than in the control, with 2.5% lime juice having higher values of all.
Table 4: Effect of natural organic acids on internal organs and bile of broilers
Parameter
Proventriculus
Gizzard
Liver
Pancreas
Kidney
Spleen
Heart
Lungs
Gall bladder
Bile volume
Small intestine
Caecum
Large intestine
T1(0ml kg-1)
0.36
2.11
1.50
0.22
0.25b
0.09
0.42
0.62
0.05c
0.01c
3.09a
0.59
0.11
T2(10ml kg-1)
0.37
1.94
1.51
0.21
0.34b
0.13
0.47
0.50
0.10b
0.05b
3.08a
0.51
0.10
T3(15ml kg-1)
0.37
1.91
1.42
0.21
0.36b
0.11
0.47
0.48
0.10b
0.06b
2.85a
0.50
0.09
T4(20ml kg-1)
0.37
2.11
1.51
0.23
0.38b
0.12
0.50
0.50
0.14a
0.09a
2.89a
0.47
0.14
T5(25ml kg-1)
0.44
1.99
1.42
0.22
0.43a
0.10
0.45
0.59
0.14a
0.09a
2.39b
0.53
0.12
SEM
0.09
0.56
0.11
0.04
0.16
0.05
0.12
0.15
0.03
0.003
0.50
0.10
0.02
ab Means along the same row with different superscripts are significantly (P<0.05) different.
The reverse was observed in small intestine which was heavier in the control compared to lime juice. The heavier
weight of small intestine in the control could be ascribed to higher population of bacteria. Organic acids reduced
bacteria mass in the gut as reported by Dibner (2004) and Ndelekwute et al. (2012). The heavier gall bladder
could have been resulted from the increase in bile volume probably induced by the lime juice. Dibner (2004) and
Ndelekwute et al. (2013) found that organic acids enhanced bile secretion.
In this study, kidney weight in the treated groups was higher than in control. This could be as a result of the
kidney responding to presence of lime juice which contained organic acids. This did not agreed with Ndelekwute
et al. (2012) who observed bigger kidney in control than in the organic acid supplemented groups. However,
Islam et al. (2008) found no significant effect,
Nutritive value of the meat
Table 5 shows the effect of treatment on nutritive value of the broiler meat. There were no significant differences
(P>0.05) in all the nutritive value parameters measured. Also the pH level of the meat was not significant
(P>0.05). This is an indication that treatment did not affect the quality of the meat negatively. Insignificant level
of pH shows that the organic acids did not accumulate in the meat indicating that probably the acids were well
metabolized. Organic acids such as citric acid are involved in metabolic process of the body especially in
carbohydrate metabolism (Bender and Mayes, 2006). Farmers have expressed fears about accumulation of organic
acids in broilers fed diets containing organic acids for a long period as in feeding of antibiotics.
Table 5: Effect of Natural Organic Acids on Nutritive value and pH of Broiler meat
Parameter
Moisture content (%)
Crude protein (%)
Ether extract (%)
Crude fibre (%)
Ash (%)
pH
T1(0ml kg-1)
77.22
23.00
0.85
0.11
1.09
6.00
T2(10ml kg-1)
76.80
23.50
0.81
0.10
1.06
6.05
T3(15ml kg-1)
77.14
23.08
0.86
0.10
1.08
6.08
T4(20ml kg-1)
76.99
23.45
0.89
0.10
1.06
6.07
T5(25ml kg-1)
77.21
22.99
0.87
0.11
1.08
6.09
SEM
11.81
5.17
0.19
0.01
0.17
1.09
ab Means along the same row with different superscripts are significantly (P<0.05) different.
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Ndelekwute et al., 2015
Published June, 2015
Economic benefit
The addition of lime juice to the diet (Table 6) led to marginal but progressive increase in the cost per kg feed
because of increasing level of lime juice. In addition, feed cost per gain and feed cost per bird were not
significant (P>0.05). This portrays lime juice as economical natural feed additive. The revenue and gross margin
were significant and followed the same trend. Except 1.0% that was similar to the control, other levels of lime
juice gave higher values of revenue and gross margin. The higher revenue was due to the influence of lime juice
on the live weight and subsequently the selling price of the birds.
Table 6: Effect of natural organic acids on economics of broilers
Parameter
Cost/ kg
Cost/ bird
Cost/ gain
Revenue
Gross margin
T1(0ml kg-1)
94.46
407.94
225.69
1653c
1245.06c
T2(10ml kg-1)
94.73
410.65
222.62
1683.24bc
1272.5bc
T3(15ml kg-1)
94.88
413.39
222.97
1702.32b
1288.93b
T4(20ml kg-1)
95.03
415.72
217.62
1731.75ab
1319.05ab
T5(25ml kg-1)
95.18
420.18
229.71
1756.2a
1345.02a
SEM
10.12
21.00
13.90
45.79
51.22
ab Means along the same row with different superscripts are significantly (P<0.05) different.
CONCLUSION
From this result, it could be inferred that dietary supplementation of broiler diet with lime juice as source of
natural organic acids, improved economic returns and had no detrimental effect on carcass yield, internal organs
and nutritive value of the meat. Therefore, 20mls/kg feed (2.0%) of lime juice could be added to broiler diets for
profit maximization.
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