ABSTRACT

African yam bean (AYB) meal and Nutrase-xyla enzyme were evaluated for their nutritive and economic efficiency in broiler diets. Six diets were formulated, a control (D1) and five others. AYB meal and fish meal were the major plant and animal protein sources. Diet 2, 3, 4, 5 and 6 were supplemented with nutrase — xyla enzyme at lOg/100 kg, 20g/100 kg, 30g/ 100 kg, 40g/100 kg and 50g/100 kg diet, respectively. The calculated percent crude protein of the diets was 25 while metabolizable energy was 3,100 kcal/kg. One hundred and forty four (144) day- old unsexed Anak 2000 strains of broiler chicks were used for the trial. Each treatment consisted of 3 replicates of 8 birds in a Completely Randomized Design (CRD). The experiment lasted 5 weeks. The results showed that the mean body weight gain and feed- to — gain ratio were significantly (P < 0.05) depressed. D1 had the highest body weight gain (603.02 g) while diets 2,3 4, 5 and 6 were 331.66g, 300.83g, 300.56g, 342.36 and 341.25, respectively. The total revenue realizable from Diet I (N361, 81) was significantly ( P< 0.05) higher than the other diets. It was therefore concluded that the use of AYB with or without nutrase — xyla enzyme supplementation is not efficient and research efforts need be made towards the provision of appropriate characterization of AYB carbohydrate, protein and anti-nutritional components to allow for development of appropriate enzymes and toxin binders that could enhance their nutritive value and utilization.

TABLE OF CONTENTS

Title Page

Certification iii

Declaration iii

Dedication iv

Acknowledgement v

Table of contents vi

List of tables viii

Abstract x

CHAPTER ONE

1.0 Introduction 1-4

1.2 Statement of Problem 4-6

1.3 The justification 6

1.4 Objectives 6-7

CHAPTER TWO

2.0 Literature Review 8

2.1 Agronomical background of African Yam bean 9

2.2 Nutritional Composition of African yam bean 9-15

2.3.0 Factors that limit the use of legumes 15

2.3.1 Flatulence factors 15

2.3.2 Antinutritional factors (ANFS) 16

2.3.3 Protease inhiubitors/ trypsin in-hibitors 17

2.4.1 Enzyme and supplementation 17-19

2.4.2 Monogastric animal nutrition & exogenous enzyme 18-22

2.5 Experimental trails using enzymes 22-23

2.6 Limitations to enzyme usage in Nigeria 24-25

CHAPTER THREE

3.0 Materials and Methods 26

3.1 Processing test ingredients 26

3.2 The experimental site 26

3.3.1 Experimental diet and their composition 28

3.3.2 Experimental birds, management and design 28

3.4 Response criteria 29

3.5 Statistical analysis 29

CHAPTER FOUR

4.1 Results and Discussion 30

4.2 percentage composition of African Yam bean- based

diets containing varying levels of nutrase xyla enzyme

fed to broiler chicks (1-35) diets 31

CHAPTER FIVE

5.1 Conclusion and recommendation 32

References 34

Appendices