ABSTRACT
A study was conducted with 300 “Bachelor” Brown laying birds to determine the
performance, egg quality characteristics and serum biochemistry of laying birds
fed diets containing neem leaf meal. The birds were randomly selected at
nineteenth week of age into five treatment groups with three replicates per
treatment with each replicate containing twenty birds. The experiment was laid out
in a completely randomized design (CRD). Five isocaloric and isonitrogenous diets
designated as T1, T2, T3, T4 and T5 containing neem leaf meal at 0, 2, 4, 6 and
8% levels of diets were fed to the birds. Proximate analysis of neem leaf meal on
dry matter basis was carried out. The birds’ performances were measured and
calculated on daily basis in terms of average feed intake, average body weight
change, feed conversion ratio, egg number, hen day egg production and economics
of egg production. Twenty four eggs per treatment at eight eggs per replicate were
collected and analyzed for both internal and external quality. Blood samples were
collected from nine birds per treatment at three birds per replicate and used to
determine the serum biochemical indices, which included serum cholesterol,
creatinine, albumen, glucose, high density lipoprotein, low density lipoprotein,
triglyceride and urea. Data obtained from the proximate analysis of the neem leaf
meal showed that the processed neem leaf meal had a crude protein of 21.76%,
crude fibre of 17.81%, ether extract of 3.68%, ash of 7.04% and nitrogen-free
extract of 49.71%, respectively. Results for average feed intake revealed that birds
fed diet 1 (control) consumed significantly (p < 0.05) higher feed (149.74g) which
was similar (p > 0.05) to those of birds fed diet 2 (147.95g), but differed
significantly (p < 0.05) from the feed intake of birds fed diets 3 (143.50g), 4
(138.41g) and 5 (133.10g), respectively, which were themselves different from
each other. Effect of diet on average egg production differed significantly (p <
0.05) with higher value of 52 for birds fed diet 5, while birds fed diets 1 (49), 3
(49) and 4 (50) had similar (p > 0.05) values which differed significantly (p < 0.05)
from birds fed diet 2 (47). Dietary treatment effect on cost benefit showed that
birds fed diet 1 (control) had the highest (p < 0.05) cost/kg of feed, cost/dozen egg,
cost of feed consumed/bird and feed cost per kg egg produced among the treatment
groups. Effect of dietary treatment on albumen weight showed that birds fed diets
2 (36.72g) and 3 (36.02g) were similar (p > 0.05) to each other but were
significantly (p < 0.05) higher than those fed diets 1 (35.61g), 4 (35.59g) and 5
(35.95g), which were themselves similar (p > 0.05) to each other. Data obtained for
albumen width was significantly (p < 0.05) higher for birds fed diet 4 (82.86mm)
which was similar (p > 0.05) to birds fed diet 2 (82.46mm), 3 (82.39mm) and 5
(82.06mm), which were themselves similar (p > 0.05) to each other, but was
different from that fed diet 1 (control) with value of 81.70mm. Birds fed diets 3
xiii
(0.38) and 2 (0.37) were similar (p > 0.05) for yolk index, but differed significantly
(p < 0.05) from those fed diets 1 (0.35), 4 (0.36) and 5 (0.36), which were
themselves similar (p > 0.05) to each other. Yolk colour differed significantly (p <
0.05) with eggs of birds fed diet 5 having a superior value of 9.6, while eggs of
birds fed diets 1, 2, 3 and 4 had respective values of 2.1, 3.9, 4.4 and 7.8, which
were significantly (p < 0.05) different from each other. Yolk cholesterol values
were significantly (p < 0.05) different among the dietary groups, with birds fed diet
5 (4.96) having the least value, while birds on diets 1, 2, 3 and 4 had values of
12.23, 9.23, 7.85 and 6.32 respectively, which differed significantly (p < 0.05)
from themselves. Effect of dietary treatment on egg shell thickness showed that
eggs of birds fed diets1 (0.47mm) and 2 (0.46mm) were superior (p < 0.05) to
those of birds fed 3 (0.41mm), 4 (0.42mm) and 5 (0.43mm) which were also
similar (p > 0.05) to each other. Eggs of birds fed diet 2 had a significantly (p <
0.05) higher mean shell weight of 9.31g, which was different from the mean shell
weight eggs of birds fed diets 1 (7.86g) and 5 (7.96g), which were themselves
similar (p > 0.05) to each other and to those of birds fed diets 3 (8.62g) and 4
(8.60g) which were similar (p > 0.05) to each other also. Results of serum
cholesterol were significantly (p < 0.05) different among the dietary groups. Birds
fed diet 1 had the highest value of 184.33mg/dl, which differed significantly (p <
0.05) from those of birds fed diets 5 (101.21mg/dl). Birds fed diets 2, 3 and 4 had
serum cholesterol values of 177.17mg/dl, 148.13mg/dl and 119.27mg/dl,
respectively which were also significantly (p < 0.05) different from each other.
Data obtained for albumen was highest (p < 0.05) in birds fed diet 5 (1.65g/dl),
which was similar (p > 0.05) to that of birds fed diet 2 (1.60g/dl), but differed (p <
0.05) from birds fed diets 1 (1.57g/dl), 3 (1.55g/dl), and 4 (1.58g/dl), which were
themselves similar (p > 0.05) to each other. It is evident from the present study that
neem leaf meal can be incorporated into the diet of laying birds up to 8% without
any negative or declining effect on the egg production and egg quality
characteristics and eventually leads to a cheaper, better egg choice with low level
of cholesterol in the eggs.
1
TABLE OF CONTENTS
Title page – – – – – – – – – – i
Certification- – – – – – – – – – ii
Dedication – – – – – – – – – – iii
Acknowledgement – – – – – – – – iv
Table of Contents – – – – – – – – – v
List of Tables – – – – – – – – – x
List of Figures – – – – – – – – – xi
Abstract – – – – – – – – – – xii
CHAPTER ONE
Introduction – – – – – – – – – 1
1.1 Objectives of the study – – – – – – – 7
1.2 Justification of the study – – – – – – – 8
CHAPTER TWO
Literature Review – – – – – – – – 9
2.1 Place of domestic chicken in meat supply – – – – 9
2.2 Poultry nutrition – – – – – – – – 14
2.3 Nutrient requirements of egg laying chickens – – – – 15
2.3.1 Energy requirements – – – – – – – 19
2.3.2 Protein and amino acid requirement – – – – – 20
2.3.3 Water requirements – – – – – – – 22
2.3.4 Mineral requirements – – – – – – – 23
2.3.5 Vitamin requirements – – – – – – – 24
vi
2.4 Leaf meals in poultry nutrition – – – – – – 25
2.5 Utilization of leaf meals in poultry – – – – – 27
2.6 Anti-nutritional factors – – – – – – – 32
2.7 Neem tree – – – – – – – – – 35
2.8 Applications of neem in animal feeds – – – – – 37
2.9 Cholesterol – – – – – – – – – 39
2.10 Cholesterol reducing effects of leaf meal – – – – 41
2.11 Serum biochemistry studies – – – – – – 43
CHAPTER THREE
Materials and Methods – – – – – – – – 47
3.1 Location and duration of study – – – – – – 47
3.2 Experimental design – – – – – – – – 47
3.3 Processing of neem leaves – – – – – – – 47
3.4 Experimental diets – – – – – – – – 49
3.5 Management of experimental birds – – – – – 52
3.6 Response parameters – – – – – – – – 52
3.6.1 Performance characteristics – – – – – – 52
3.7 Statistical analysis – – – – – – – – 58
CHAPTER FOUR
Results – – – – – – – – – – 60
4.1 Proximate composition of neem leaf meal – – – – 60
4.2 Performance of laying birds – – – – – – – 61
4.1.1. Average final body weight – – – – – – 61
4.1.2. Average daily feed intake – – – – – – 61
4.1.3. Average body weight change – – – – – – 63
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4.1.4. Feed conversion ratio – – – – – – – 63
4.1.5. Average egg production – – – – – – – 63
4.1.6. Hen day egg production – – – – – – – 64
4.1.7. Cost benefits – – – – – – – – 64
4.2. Internal egg qualities of birds – – – – – – 65
4.2.1. Albumen weight – – – – – – – – 65
4.2.2. Albumen height – – – – – – – – 65
4.2.3. Albumen width – – – – – – – – 65
4.2.4. Albumen index – – – – – – – – 66
4.2.5. Yolk weight – – – – – – – – 66
4.2.6. Yolk height – – – – – – – – – 66
4.2.7. Yolk width – – – – – – – – – 67
4.2.8. Yolk index – – – – – – – – – 67
4.2.9. Yolk color – – – – – – – – – 67
4.2.10. Haugh unit – – – – – – – – 68
4.2.11 Yolk cholesterol – – – – – – – – 68
4.3. External egg qualities of birds – – – – – – 70
4.3.1. Egg weight – – – – – – – – – 70
4.3.2. Egg length – – – – – – – – – 70
4.3.3. Egg width – – – – – – – – – 70
4.3.4. Egg shape – – – – – – – – – 71
4.3.5. Egg shell thickness – – – – – – – 71
4.3.6. Shell weight – – – – – – – – 71
4.4. Serum biochemical indices of birds – – – – – 73
4.4.1. Serum cholesterol – – – – – – – – 73
viii
4.4.2. Creatinine – – – – – – – – – 73
4.4.3. Albumen – – – – – – – – – 73
4.4.4. Glucose – – – – – – – – – 74
4.4.5. High density lipoprotein – – – – – – – 74
4.4.6. Low density lipoprotein – – – – – – – 75
4.4.7. Triglyceride – – – – – – – – – 75
4.4.8. Urea – – – – – – – – – – 75
CHAPTER FIVE
Discussion – – – – – – – – – – 78
5.0. Proximate composition of neem leaf meal – – – – 78
5.1. Performance of laying birds – – – – – – 79
5.1.1. Average daily feed intake – – – – – – 79
5.1.2. Average daily weight change – – – – – – 81
5.1.3. Feed conversion ratio – – – – – – – 83
5.1.4. Percentage hen day egg production – – – – – 84
5.1.5. Cost benefits – – – – – – – – 85
5.2. Internal egg qualities – – – – – – – 86
5.2.1. Albumen weight – – – – – – – – 86
5.2.2. Albumen height – – – – – – – – 87
5.2.3. Albumen width – – – – – – – – 87
5.2.4. Albumen index – – – – – – – – 88
5.2.5. Yolk weight – – – – – – – – 89
5.2.6. Yolk height – – – – – – – – – 89
5.2.7. Yolk width – – – – – – – – – 89
5.2.8. Yolk index – – – – – – – – – 90
ix
5.2.9. Yolk color – – – – – – – – – 91
5.2.10. Haugh unit – – – – – – – – – 92
5.3 External egg qualities of birds – – – – – – 92
5.3.1. Egg weight – – – – – – – – – 92
5.3.2. Egg length – – – – – – – – – 94
5.3.3. Egg width – – – – – – – – – 94
5.3.4. Egg shape index – – – – – – – – 94
5.3.5. Egg shell thickness – – – – – – – 95
5.3.6. Shell weight – – – – – – – – 96
5.4 Yolk cholesterol – – – – – – – – 97
5.5 Serum biochemical indices of birds – – – – – 98
5.5.1. Serum cholesterol – – – – – – – – 98
5.5.2. Serum creatinine – – – – – – – – 99
5.5.3. Serum albumen – – – – – – – – 100
5.5.4. Serum glucose – – – – – – – – 101
5.5.5. High density lipoprotein – – – – – – – 101
5.5.6. Low density lipoprotein – – – – – – – 102
5.5.7. Triglycerides – – – – – – – – 102
5.5.8. Serum urea – – – – – – – – – 103
CHAPTER SIX
Summary and Conclusion – – – – – – – 104
6.1. Summary – – – – – – – – – 104
6.2. Conclusion – – – – – – – – – 106
REFERENCES – – – – – – – – – 107
APPENDICES – – – – – – – – – 120
x
CHAPTER ONE
1.0 INTRODUCTION
Nigeria is the largest economy in Africa with a population of over 174
million persons. This amazing data calls for a sustained approach to provide its
citizens with quality food especially safe and affordable animal protein.
Unfortunately, the level of animal protein intake is absolutely low at 4.5g/day per
caput (USDA, 2013). This level of animal protein intake is not befitting of a nation
that is the largest economy in Africa and the 26th in the world.
Poultry production remains the fastest means to provide animal protein to a
protein hungry nation like Nigeria. Poultry meat and egg are still widely consumed
with little or no religious or social constraints. Egg has been described as nature’s
convenience food since it comes in a hygienic pack and can easily be stored and
readily opened and cooked. Also eggs are valuable and acceptable in the diets of
younger and older people whose caloric needs are lower and who sometimes have
difficulty in chewing certain types of food (Oluyemi and Robert, 2007). Egg is a
good source of low cost high quality protein providing 6.3grams of protein (13%
of the daily value for protein) in one egg for a caloric cost of only 68 calories
(Oluyemi and Robert, 2007). The structure of humans and animal is built on
protein. Man relies on animal and vegetable protein for the supply of amino acids.
2
The body rearranges the nitrogen to create the pattern of amino acids required.
Chicken egg is the most commonly eaten poultry product that is capable of
supplying all the essential amino acids for humans while also providing several
vitamins such as vitamin A, riboflavin (vitamin B2), folic acid (vitamin B9),
vitamin B6, vitamin B12, choline and minerals such as iron, calcium, phosphorus
and potassium (Oluyemi and Robert, 2007). It is worth noting that all of the egg’s
fat soluble vitamins A, D and E are in the egg yolk (Chris, 2005). As a food, yolks
contain all of the egg’s fat and cholesterol, and about one-fifth of the protein
(Oluyemi and Robert, 2007). The yolk makes up about 33% of the liquid weight of
the egg. It contains approximately 60 calories, three times the caloric content of the
egg white. The yolk of one egg (grade one) contains approximately 2.7g protein,
210mg cholesterol, 0.61g carbohydrate and 4.51g total fat (USDA, 2013). Egg
yolks also contain the long chain Omega-3-fatty acid deoxyhydroxynucleic acid
(DHA) which is necessary for the brain and proper retinal function in the eye, and
the long chain Omega-6-fatty acid, arachidonic acid (AA) which is required for
healthy skin, hair, libido, reproduction, growth and response to injury (Chris,
2005). These fatty acids are primarily needed by young children, pregnant and
lactating women and people with degenerative diseases involving oxidative stress,
especially those of the nervous system such as Alzheimer (Garrigus, 2007).
According to National Cholesterol Education Programme (1991), one egg yolk
3
contains 75mg of arachidonic acid (AA) and 20mg of DHA. Also, studies by
Ologhobo et al. (2008) added further evidence to the theory that an egg whose yolk
is a rich source of vision protective carotenoids, including not only lutein but also
zeaxanthin may reduce the risk of developing age related muscular degeneration
(AMD). Though egg yolk contains less lutein and zeaxanthin than other foodstuffs,
their carotenoids are easily absorbed in the retina.
4
Thus, the abundance of natural readily available amino acids, minerals and
vitamins makes the egg an important part of human diet. However, limited egg
consumption has been recommended for many years due to the considerable yolk
cholesterol content (Weggemans et al., 2001). Today, many consumers limit their
intake of egg due to the adverse publicity about saturated fats and cholesterol
whereas health professionals suggest decreasing saturated fat intake only. It is a
known fact that cholesterol at certain risk level predisposes man, especially the
present day sedentary professionals to coronary heart disease, high blood pressure,
stroke and obesity (Murray et al., 2003). Also, because of recent understanding of
the association between total plasma cholesterol and the incidence of heart disease,
people are being advised to consume not more than 300mg cholesterol daily (Lada
and Rudel, 2003) and limit their consumption of eggs, which contain about 213mg
cholesterol per egg ( National Cholesterol Education Programme, 1991).
The livestock industry in developing countries is plagued by numerous
challenges among which is scarcity of feed ingredients that are in strict
competition with man’s dietary need. The high cost of conventional feedstuff has
already sent a lot of livestock farmers out of business, thus leading to reduction in
overall animal products available for human dietary need. The provision of feed
alone has been reported to account for 60-80% of the total cost of poultry
production in developing countries (Esonu et al., 2006). In view of this, there is
5
increased interest by livestock farmers on the search for non-conventional feed
ingredients of comparable quality that are cheap such as leaf and seed meals of
ethno-medicinal plants (Okorie, 2006). In an effort to develop new feedstuff for
animal feeding, some researchers in recent times have investigated the proximate
composition of neem seed meal (Bawa et al., 2007; Uko and Kamalu, 2007) and
leaf meal (Oforjindu, 2006; Esonu et al., 2005; Ogbuewu et al., 2010) and its use
as feedstuff in poultry (Esonu et al., 2005; Oforjindu, 2006; Uko and Kamalu,
2007) and rabbits (Ogbuewu et al., 2008). Result of proximate analysis of neem
showed that neem leaf meal had 92.42% dry matter, 7.58% moisture, 20.68%
crude protein, 16.60% crude fiber, 4.13% ether extract, 7.10% ash and 43.91%
nitrogen free extract (Esonu et al., 2005; Oforjindu, 2006).
The neem is a tropical ever green tree native to Indian sub-continent. It has
been used in Ayurvedic medicine for more than 4000 years due to its medicinal
properties (Schmutterer, 1981). Most of the plant parts such as fruits, seeds, leaves,
barks and roots contain compounds with proven antiseptic, antibiotics, antiviral,
antipyretic, anti-inflammatory, anti-ulcer, antifungal and hypocholesterolemic
properties (Onyimonyi et al., 2009; Olabode, 2008; Sateesh, 1998). Neem is a
natural source of eco-friendly insecticides, pesticides and agrochemicals
(Brahmachari, 2004). The tree is adaptable to a wide range of climatic, topographic
and edaphic factors. It thrives well in dry, stony shallow soils and even on soils
6
having hard clay pan at a shallow depth. Neem tree requires little water and plenty
of sunlight (Olabode, 2008). The tree grows naturally in area where the rainfall is
in the range of 450 to 1200mm (Sateesh, 1998). However, it has been introduced
successfully even in areas where the rainfall is as low as 150 to 250mm. Neem
grows on altitude up to 1,500m (Jattan et al., 1995; Chari, 1996). It can grow well
in wide temperature range of 0 to 490C (Hegde, 1995). It cannot withstand water
logging and poor drainage. The pH range for the growth of neem trees lies between
4 to 10 (Brahmachari, 2004). Neem tree has the ability to neutralize acidic soils by
a unique property of calcium mining (Hegde, 1995).
Biologically active ingredients isolated from different parts of the plants
include; azadirachtin, meliacin, gedunin, salanin, nimbin, valassin and many other
derivatives of these ingredients (Chari, 1996). Meliacin forms the bitter principles
of neem seed oil. The seed also contains tignic acid (5-methyl-2-butanic acid)
responsible for the distinctive odour of the oil. These compounds belong to natural
products called triterpenoids (Limonoids). They also contain glutamic acid,
tyrosine, aspartic acid, alanine, proline, glutamine and cystine ( amino acids) and
several fatty acids (dodecanoic, tetradecanoic, elcosanoic e.t.c) (Olabode, 2008).
The essential oil contains sesquiterpene derivatives and also the flower contains
nimbosterol and flavonoids like kaempferol and melicitrin. The flower also yields
a waxy material consisting of several fatty acids such as, behenic (0.7%), arachidic
7
(0.7%), stearic (8.2%), palmitic (13.6%), oleic (6.5%) and linoleic (8.0%)
(Olabode, 2008). The pollen of neem contains several amino acids like glutamic
acid, tyrosine, arginine, methionine, phenylalanine, histidine, aminocaprylic acid
and isoleucine. The trunk bark contains nimbin (0.04%), nimbidin (0.001%),
nimbinene (0.4%), nimbosterol (0.03%), essential oil (0.02%), tannins (6.0%), a
bitter principle margosine and 6-desacetylnimbinene. The stem bark contains
tannins (12-16%) and non-tannin (8-11%) (Elangovan et al., 2000). The bark also
contains anti-inflammatory polysaccharide consisting of glucose, arabinose and
fructose at a molar ratio of 1:1:1 with molecular weight of 8400. Besides
polysaccharides, several diterpenoids, viz., nimbinone, nimbolicin, margocin,
nimbidiol, nimbione e.t.c have been isolated from stem bark and root bark
(Schmutterer, 1981)
1.1 OBJECTIVES OF THE STUDY
This study was designed broadly to determine the effect of incorporating
neem (Azadirachta indica) leaf meal in layers’ diet on egg production, egg quality
characteristics and serum biochemistry of laying birds. Specifically, the objectives
of the study were to evaluate the:
· egg laying performance of birds fed with diets containing different levels of
neem leaf meal (NLM),
8
· the economics of production of the eggs by birds fed diets containing
different levels of NLM
· internal and external quality characteristics of the eggs laid by the birds,
· serum biochemistry of the laying birds,
1.2 JUSTIFICATION OF THE STUDY
The growing concern about the high cost of production among poultry farmers and
the cholesterol content in eggs by consumers call for concerted efforts by animal
nutritionist to seek appropriate nutritional protocols that will reduce the cost of
producing eggs as well as reduce the cholesterol content in chicken eggs. The
result of such work will enhance the production of more eggs by poultry farmers
and thus reduce the overall cost of egg production and also re-kindle the
confidence of consumers and their interest to consume more eggs and thus be able
to derive more benefits associated with eating eggs. Thus, the present study aimed
at increasing the quantity and nutritional quality of eggs produced by laying birds
using cheap and available leafy material.
9
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