ABSTRACT

The use of housefly larvae as fish and animal feed is becoming prevalent in Nigeria and globally. Despite the possibility of differing maggot production capacities among them, no distinction is made between the origins of the manures used in the culture of housefly larvae. Musca domestica were therefore cultured in chicken broiler, chicken layer, and pig dungs. Maggot yield, heavy metals and nutrient dynamics in fresh and used dungs were studied. The heavy metals examined were Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Selenium (Se), Nitrogen (N), Phosphorus (P) and Potassium (K). Periodic maggot yield was significantly different among the manures (p<0.0001). Maggot yield was significantly affected by manure type (p<0.0001), and was significantly higher in chicken layer manure, followed by chicken broiler manure, and least in pig manure (p<0.05). The concentration of Cd, Cr, Cu, Pb, N, P, K was significantly higher in raw manure samples compared to used manure (p<0.001) across the three treatments. Se was not detected in the samples across the three treatments. Surprisingly, significantly higher maggot yield was observed at higher total heavy metal concentrations. However, maggot yield showed a significantly negative correlation with total Nitrogen, Phosphorus and Potassium (NPK).

TABLE OF CONTENTS

Title page                                                                                                                    i

Declaration                                                                                                                  ii

Certification                                                                                                                iii

Dedication                                                                                                                  iv

Acknowledgements                                                                                                    v

Table of Contents                                                                                                       vi

List of Tables                                                                                                              viii         

List of Figures                                                                                                             ix

List of Plates                                                                                                               x

Abstract                                                                                                                      xi

CHAPTER 1:            INTRODUCTION

1.1        Background of the Study                                                                               1

1.1.1        Waste materials used in aquaculture                                                               3

1.1.2    The chemical composition of chicken manure                                                3

1.1.3    Nutrient content of swine manure                                                                  5

1.1.4    Benefits and potentials of utilising insects as an alternative protein source   5

1.2       Statement of Problems                                                                                    6

1.3       Justification of the Study                                                                               6

1.4       Aim and Objectives                                                                                        7

1.4.1    Specific objectives                                                                                          7

CHAPTER 2:            LITERATURE REVIEW

2.1        Livestock Farming and Feed Production                                                       8

2.2       Use of Maggots in Animal Production and Aquaculture                               8

2.2.1    Life cycle of housefly                                                                                     10

2.2.2        Taxonomy                                                                                                       11

2.3       Nutrient Composition of Maggots                                                                  12

2.4        Utilisation of Maggot Meal in Fish Diets                                                       14

2.5        Factors Affecting Maggot Production                                                        15

2.6        Heavy Metal Content in Animal Manure                                                       16

2.7        Sources of Heavy Metal Exposure to Humans                                               18

2.7.1        Sources of specific heavy metals                                                                    18

2.7.1.1 Lead                                                                                                                18

2.7.1.2 Cadmium                                                                                                        19

2.7.1.3 Chromium                                                                                                       19

2.7.1.4 Copper                                                                                                                        20

2.8        Routes of Exposure, Bio-Uptake and Bioaccumulation of Heavy Metals

      in Humans                                                                                                       20

2.9        Animal Husbandry in Aquaculture                                                                 21

2.10     Classification of Nutrients in Poultry                                                             24

2.11     Classification of Nutrients in Piggery                                                             26

CHAPTER 3:            MATERIALS AND METHODS

3.1        Area of the Study                                                                                           27

3.2        Construction of Wooden Culture Boxes                                                        28

3.3       Experimental Procedure                                                                                  30

3.4       Production of Maggot                                                                                     32

3.5        Conversion of Swine, Broiler and Layer Manure by Maggots                      32

3.6        Heavy Metal Analysis                                                                                     32

3.6.1    Digestion procedure                                                                                        32

3.6.2    Atomic absorption spectrophotometer (AAS) Procedure                                33

3.6.3        Preparation of STANDARDS for AAS Calibration                                      34

3.7       Statistical Analysis                                                                                          35

CHAPTER 4:            RESULTS AND DISCUSSION

4.1              Results                                                                                                                        36

4.2        Discussion                                                                                                       44

4.2.1        Capacity of maggot production                                                                      44

4.2.2    Heavy metal and NPK in manure                                                                   46

CHAPTER 5:            CONCLUSION AND RECOMMENDATION

5.1       Conclusion                                                                                                      51

5.2       Recommendations                                                                                          51

REFERENCES                                                                                                        51

LIST OF TABLES

Table                                                                                                                          Page No.

4.1:      Weight of maggot production            (g)                                                                    36

4.2:      Levels of total heavy metals in manure samples (mg/l) in fresh and

            used pig, broiler and layers in raising M. domestica larvae for five-day         40

4.3:      Levels of NPK in manure samples (mg/kg) in fresh and used pig,                             broiler and layers in raising M. domestica larvae for five days                   42

4.4:      Levels of NPK in manure samples (mg/kg) in fresh and used pig, broiler

            and layers in raising M. domestica larvae per variable /element for

            five days                                                                                                         43

LIST OF FIGURES

Figure                                                                                                                         Page No.

3.1:                  Map showing area of the study                                                          27

4.1:                  Concentration of heavy metals (cadmium, chromium, copper,

and lead) (mg^.kg^-1) in chicken layer manure, before and after

the culture of Musca domestica larvae                                                37

4.2:                  Concentration of heavy metals (cadmium, chromium, copper,

                        and lead) (mg^.kg^-1) in chicken Broiler manure, before and

                        after the culture of Musca domestica larvae                                       38

4.3:                  Concentration of heavy metals (cadmium, chromium, copper,

                        and lead) (mg^.kg^-1) in pig manure, before and after the culture

                        of Musca domestica larvae                                                                  39

4.4:                  Variation in Treatment 3 with respect to maggot yield and total

                        heavy metal                                                                                         41

LIST OF PLATES

Plate                                                                                                                            Page No.

1:         Maggot production box                                                                                  29

2:         A pan for maggot production                                                                         31