ABSTRACT
The response of broiler chickens fed methanol extracts of selected medicinal plants as a replacement for antibiotics was investigated. The plant extracts encompass four available leaves; Gereinia kola (Bitter kola), Alcornea cordifolia (Christmas bush), Pterocarpus santalinus (Red scandal wood) and Chromolera odorata (Hagony or Siam weed). Antimicrobial activities, growth performance, carcass characteristics, internal organ proportions, hematological indices, serum biochemical indices and caecal microbial loads were considered. The experimental diet was same for all the treatment groups since the methanol extract of the leaves were administered in their drinking water against synthetic antibiotics. 180 unsexed Ross strain broiler chickens were randomly assigned to these dietary treatments which had 30 birds each. The treatments were replicated thrice with 10 birds per replicate in a Completely Randomized Design (CRD). Birds were fed these diets from day one; feed and water were provided ad libitum throughout the experimental period which lasted for 56 days. For growth performance at the starter phase, Treatment 2 (negative control) had the highest final body weight (920.67 g/b), average daily weight gain (31.60 g/b) and best feed conversion ratio (1.82), followed by treatment 5 (Alcornea cordifolia) which also had the highest value for feed intake (1690.33 g/b). At finisher phase, Treatment 5 (Alcornea cordifolia) had the highest final body weight (2886.66 g/b), average daily weight gain (69.52 g/b/d) and best feed conversion ratio (2.39), followed by Treatment 6 (Gereinia kola). Significant (p<0.05) differences were observed in the mean values of all the haematological parameters measured across the treatment groups except Eosinophil and Basophil at starter phase while significant (p<0.05) differences were observed only in PCV, WBC and Monocyte at the finisher phase. In serum chemistry, significant (p<0.05) differences were observed in the mean values of all the parameters measured with exception of total protein and globulin. However, the values obtained did not reveal any health problem. Carcass yield, cut parts and organ proportion of broiler chickens differed significantly (p<0.05). Treatment 5 (Alcornea Cordifolia) had a significant (P>0.05) reduction in abdominal fat when compared to the positive control group. There was no significant (P>0.05) difference in the antimicrobial activities of the methanol extracts of the selected medicinal plants. However, Treatment 5 (Alcornea cordifolia) extract had the highest and best values for the microbial activities tested for. Histomorphology indices revealed significant (p>0.05) difference for villus height and weight, crypt depth and width. Treatment 5 (Alcornea cordifolia) gave the highest nutrient absorption of the birds. It can be concluded from this study that the methanol extracts of the selected medicinal plants has considerable constituents as component of broiler chickens diet. Alcornea cordifolia methanol plant extract can successfully be used to replace antibiotics both for starter and finisher phases of broiler production. Further research should be carried out on Alcornea Cordifolia and other medicinal plants to mitigate potential adverse effects on growth performance.
TABLE OF CONTENTS
Title Page i
Declaration ii
Certification iii
Dedication iv
Acknowledgments v
Table of Contents vi
List of Tables ix
Abstract xi
CHAPTER
1: INTRODUCTION
1.1 Background of the study
1
1.2 Statement of Problem
3
1.3 Objectives of the Study 4
1.4
Justification of the Study 5
CHAPTER
2: LITERATURE REVIEW
2.1
Effects of antibiotics on poultry and human lives
7
2.1.1 Antibiotics and bacteria
resistant
7
2.1.2 Alternative to the use of
antibiotics
8
2.2 Impact of medicinal plant in
livestock production
9
2.3 Blood as a Component in Animal
Nutritional Studies
11
2.3.1 Significance of haematological
profile in nutritional studies of broiler chicken 12
2.3.2 Significance of Serum Biochemical
Profile in Nutritional Studies of Broiler Chicken 16
2.4 General overview of medicinal
plant extract in poultry production 22
2.4.1 Gercinia kola (Bitter kola)
22
2.4.2 Alcornea cordifolia (Christmas bush)
34
2.4.3 Chromoleana odorata (Siam weed)
45
2.4.4 Pterocarpus santalinus (Red sandal wood)
51
2.5 Effect of ceacal microflora load
on broiler chicken
56
2.6 Effect of histomorphology of
broiler chicken fed methanol extracts of medicinal plants 59
CHAPTER
3: MATERIALS AND METHODS
3.1 Experimental site and location 60
3.2 Duration of study 60
3.3 Preparation of the plant extracts 60
3.3.1 Screening of
the extract for antimicrobial activity 61
3.4 Experimental birds and management 65
3.5 Experimental
diets 66
3.6 Experimental
designs and data collection 66
3.7 Statistical analysis 76
CHAPTER
4: RESULTS AND DISCUSSION
4.1 Growth performance of broiler
chickens fed methanol extracts of selected medicinal plants 77
4.2 Haematologiical profile of
broiler chickens fed methanol extracts of selected medicinal plants 81
4.3
Serum biochemical profile of broiler chickens fed methanol extracts of selected
medicinal plants 86
4.4
Growth performance of finisher broiler chickens fed methanol extracts of
selected medicinal
plants
91
4.5 Carcass yield and cut-parts of
finisher broiler chicken fed methanol extracts of selected medicinal
plants 94
4.6 Internal organ proportion of
finisher broiler chicken fed methanol extracts of selected medicinal
plants 97
4.7 Haematological profile of
finisher broiler chicken fed methanol extracts of selected medicinal
plants
100
4.8 Serum biochemical profile of
finisher broiler chicken fed methanol extracts of selected medicinal
plants
104
4.9 Total heterotrophic bacteria
count of broiler chicken fed methanol extracts of selected medicinal
plants 109
4.10 Histormorphology of broiler
chicken fed methanol extracts of selected medicinal plants 112
4.11 Antimicrobial activities of
medicinal plants 120
CHAPTER
5: SUMMARY, CONCLUSION AND RECOMMENDATIONS
5.1 Summary
124
5.2 Conclusion 125
5.3 Recommendations
125
References 127
LIST OF TABLES
2.1 Nutrient composition of Garcinia kola 27
2.2 Phytochemical constituents of Garcinia kola 28
2.3 Proximate composition of Chromolena odorata leaf meal 48
2.4 Chemical composition of Pterocarpus santalinus leaf meal 52
2.5 Phytochemical composition of Pterocarpus santalinus leaf meal 53
3.1 Ingredients and nutrient composition of
experimental diet
66
4.1 Growth performance of broiler chickens fed
methanol extracts of selected medicinal plants 78
4.2 Haematologiical profile of
broiler chickens fed methanol extracts of selected medicinal plants 82
4.3 Serum biochemical profile of broiler chickens fed
methanol extracts of selected medicinal plants
4.4 Growth performance of finisher broiler chickens
fed methanol extracts of selected medicinal plants 92
4.5 Carcass yield and cut-parts of finisher broiler
chicken fed methanol extracts of selected medicinal plants 95
4.6 Internal organ proportion of finisher broiler
chicken fed methanol extracts of selected medicinal plants 98
4.7 Haematological profile of finisher broiler chicken
fed methanol extracts of selected medicinal plants
101
4.8 Serum biochemical profile of
finisher broiler chicken fed methanol extracts of selected medicinal
plants
105
4.9 Total heterotrophic bacteria
count of broiler chicken methanol extracts of selected medicinal plants
110
4.10 Histormorphology of broiler chicken fed methanol
extracts of selected medicinal plants
113
4.11
Antimicrobial activities of the selected
medicinal plants 121
LIST OF FIGURES/PLATES
3.1 Chromoleana
odorata leaf 63
3.2 Pterocarpus
santalinus leaf 63
3.3 Garcinia
kola leaf 64
3.4 Alcornea
cordifolia leaf 64
5.1 Photomicrograph
of the small intestine of chicken from positive control treatment group 114
5.2 Photomicrograph
of the small intestine of chicken from negative control treatment group 115
5.3 Photomicrograph
of the small intestine of chicken from Chromoleana
odorata treatment group 116
5.4 Photomicrograph
of the small intestine of chicken from Pterocarpus
santalinus treatment group 117
5.5 Photomicrograph
of the small intestine of chicken from Alcornea
cordifolia treatment group 118
5.6 Photomicrograph
of the small intestine of chicken from Garcinia
kola treatment group 119
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
The significance of the poultry industry to the
socioeconomic development of any country cannot be overstated as a result of
its ability to provide animal protein at a relatively shorter duration and at
reasonable cost to the consumer (Bonsu et
al., 2012). Therefore, broiler
farming seems to be a considerable part of meat production and consumption in
Nigeria. In the past two decades, broiler production has grown dramatically;
these improvements are largely due to numerous researches and breeding programs
which further enhanced feed usage, growth rate and low levels of activity.
Consequently,
livestock represents an important source of high quality animal protein,
providing about 36.5 percent of the total protein consumptions of Nigerians. It
is one of the highest investments in agriculture with a net worth of N250
billion (http://www.aicpnigeria.org)
Poultry
farming is the process of raising farm birds such as chickens, ducks, turkeys,
and geese with the purpose of producing meat or eggs for food. Poultry mostly
chickens are farmed in large quantities. Farmers raise more than 50 billion
chickens annually as a source of norishment, both for their meat and for their
eggs (Compassion in World Farming, 2018).
Antibiotics
have been widely used to prevent, control and treat bacterial diseases in food
animals. In poultry, antibiotics used for therapeutic purposes are usually
added to water while antibiotics for growth promotion are added to feeds
(Gentle et al, 1982). Global sales of
veterinary antimicrobial agents run into several tons per annum (Kuenzel, 2001).
During the last decade, the use of antibiotics for growth promotion and
therapeutic treatment in food animals has raised serious public health concern
because of the increasing problem of antibiotic resistance among bacterial
pathogens (Grandin et al, 2005), the
widespread and often unregulated use of antibiotics to keep animals healthy and
promote growth has been identified as a major factor responsible for breeding
new forms of antibiotic resistance. The reservoir of resistant bacteria in food
animals poses a potential risk of transfer of resistant bacteria or resistance
genes from food animals to humans (Singer and Peter, 2006).
Furthermore,
the failure of antibiotics is increasing the cost of livestock production as
well as economic losses due to untreated infections. In efforts to slow down
the rate of spread of antibiotic resistance bacteria, several countries have
seen the need to regulate or ban the use
of certain antibiotics as growth promoters in food animals (Caston, 2011).
The
situation calls for an urgent need to search for alternatives to antibiotics
which will produce the desired results in farms with minimal or no side effect
to humans. New approaches that are receiving attention include vaccination,
improvement of the gut bacteria flora using probiotics and prebiotics, use of
phages, research on antimicrobial peptides and use of predatory bacterial
(Ogle, 2016). One potential source of new antibacterial agents for use in
poultry as replacement for antibiotics is medicinal plants.
Medicinal
plants are commonly used in traditional folkloric medical practice to treat
varieties of ailments including microbial infections. Ethnobotanical surveys in
different places have documented the uses of many medicinal plants (Licherman,
2004, Collins and Minta, 2000). In-vitro
evaluation of the antimicrobial activities of several of these medicinal plants
has been reported. These plants with antimicrobial properties are potential
sources of materials for further research for discovery and development of
antimicrobial agents for use in poultry production. In the ethnobotanical
survey conducted by Tapsell et al,
(2006), the authors documented 88 plant species belonging to 47 families, which
small holder farmers in Eastern Uganda use for treatment of poultry
diseases. Many of these medicinal
plants have not been scientifically studied to validate the efficacy and to
identify the phytochemical constituents that may be responsible for their
medicinal values.
Research
on such plants could result in discovery of compounds that could be developed
into useful agents for replacement of antibiotics in poultry production. Medicinal
Plant methanol extracts also have an appetizing and digestion stimulating
properties and antimicrobial effect. According to Stepp and John (2004) leaf
vegetables supply minerals, proteins and vitamins which could compliment the
inadequacy of most feed stuffs. Sumner and Judith, (2000) reported that leaf
protein has the potential for supplying good quality food protein that could
also be obtained with cereals, legumes and oil seeds. They are also rich in
potassium, calcium and magnesium (Mills and Frank, 2000)
All
these have their challenges and limitations, though the utilization of plant
and leaf extracts in animal production have found wide spread scientific and
commercial acceptance as a strategy to improve the health status and
performance of the animals. Hence, the aim of this research work is to
investigate the response of broiler chickens fed on methanol extracts of
selected medicinal plants as alternative to antibiotics in poultry production.
1.2 STATEMENT OF THE
PROBLEM
Nutrition
has been a major determinant of profit in livestock business as feeding
accounts for about 70-80% of the costs of producing livestock, most especially
poultry (Onunkwo et al., 2018). High cost of feed has been one of the key
factors militating against the development of poultry, resulting from a
cumulative effect of cost of feed ingredient used in feed production. In
Nigeria, concerted efforts have been given to alternative macro feed
ingredients especially from agro-industrial by-products and feedstuffs to solve
this costly feed problem. These ingredients have been used mainly to resolve
the high cost of energy and protein ingredient in livestock production. Methanol
extract of medicinal plant, an important additive, which contribute
substantially to animal well-being in terms of providing essential
micro-nutrients and improved gut performance have however not received the same
attention.
Though
these additives are normally incorporated into the diet at a relatively low
level, such inclusions often come with a very large chunk of the total
financial outlay earmarked for the feed component of the livestock enterprise.
The reason for this is that most of the additives used in the developing
country like Nigeria are imported, and hence sold to the local livestock
farmers at a cost that is usually not affordable and mostly unbearable to them.
Furthermore, the additive is synthetic and non-biodegradable in nature, also
information on how to assemble feed additives is limited because such is the
manufacturer’s trade secret. Direct method of reducing cost of production and
increasing profitability has been traced to the use of alternativelocally
available and cheap feed additives amongst which are Garcinia kola, Alchornea cordifolia, Pterocarpus santolinoides and chromolaena odorata which would be used
in this research.
1.3
OBJECTIVES OF THE STUDY
The broad objective of this study is to
investigate the response of broiler chickens fed methanol extracts of selected
medicinal plants as alternative to antibiotics.
The specific
objectives of the study were to determine:
i.
The in-vitro
antibacterial activities of methanl extracts of Garcinia kola, Alchornea cordifolia, Pterocarpus santolinus and chromolaena odorata.
ii.
The growth performance of
broiler chickens fed methanl extracts of Garcinia
kola, Alchornea cordifolia, Pterocarpus santolinus and chromolaena.
iii.
The haematological
indices of broiler chickens fed methanl extracts of Garcinia kola, Alchornea cordifolia, Pterocarpus santalinus and chromolaena odorata.
iv.
The serum biochemical
assay of broiler chickens fed methanol extracts of Garcinia kola, Alchornea cordifolia, Pterocarpus santolinus and chromolaena odorata.
v.
The caecal microflora of
broiler chickens fed methanl extracts of Garcinia
kola, Alchornea cordifolia, Pterocarpus santolinus and chromolaena odorata.
vi.
The carcass
characteristics and internal organs proportions of broiler chickens fed methanl
extracts of Garcinia kola, Alchornea
cordifolia, Pterocarpus santolinus and chromolaena
odorata.
vii.
The histomorphology of
broiler chickens fed methanl extracts of Garcinia
kola, Alchornea cordifolia, Pterocarpus santolinus and chromolaena odorata.
1.4 JUSTIFICATION OF THE STUDY
The
profit of broiler farming mainly depends on economic feeding of balanced, cheap
and quality diets. The current global emphasis in broiler production is the
formulation of feed at least cost, also free as much as possible of synthetic
products (organic feed) owing to the deleterious side effects of consistent
consumption of non-biodegradable synthetic products on both animals and human
health. The discovery that the use of antibiotics in food animals is fueling
the increasing problem of antibiotics resistance and the associated risk of
transmitting resistance bacteria from food animals to man has to the search for
an alternative to the use of antibiotics. Researchers are employing various
approaches including development of vaccines, probiotics and prebiotics and
antibacterial peptides such as bacteriocins. These approaches have their
challenges and limitations. Medicinal plants have not been particularly
explored as a possible source of antibacterial agents in this regard.
Search
for antibacterial agents from medicinal plants for use in animal feed have not
been adequately addressed, although, many medicinal plants have been screened
for antimicrobial activities with the intention of finding novel compounds that
could be used as replacement for antibiotics in livestock production. It is
hoped that this effort will lead to recommending the methanol extracst suitable
medicinal plant as alternative to antibiotics to poultry producers.
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