DETERMINATION OF THE TRUE METABOLIZABLE ENERGY OF SOME NON-CONVENTIONAL AGRO-INDUSTRIAL BY-PRODUCTS

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TABLE OF CONTENTS

Title page ……………………………………………………………………………i

Certification …………………………………………………………………………..ii

Dedication…………………………………………………………………………iii

Acknowledgement…………………………………………………………………iv

Table of contents …………………………………………………………………..v

List of tables ……………………………………………………………………..viii

Abstract……………………………………………………………………………ix

CHAPTER ONE: Introduction

  1. Background………………………………………………………………….1
  2. Statement of the problem……………………………………………………3
  3. Objectives of the study………………………………………………………4
  4. Justification………………………………………………………………….4

CHAPTER TWO: Literature Review

2.1     Metabolizable energy ………………………………………………………….6

2.1.1  Apparent metabolizable energy ………………………………………………..8

2.1.2  True metabolizable energy …………………………………………………….8

2.2     Merits of true metabolizable energy assay …………………………………10

2.3     Assumptions of metabolizable energy …………………………………….11

2.4     Sources of error in true metabolizable energy assay ………12

2.5     Factors affecting metabolizable energy …………………………………………13

2.5.1  Species of birds ……………………………………………………………13

2.5.2  Age of birds …………………………………………………………………13

2.5.3  Sex of birds …………………………………………………………………14

2.5.4  Feed input …………………………………………………………………….14

2.5.5  Pelleted and mashed diets …………………………………………………15

2.5.6  Acclimatization to change of diets …………………………………………15

2.5.7  Starvation period …………………………………………………………..16

2.5.8  Nutrient deficiency …………………………………………………………16

2.5.9  Excreta collection period ……………………………………………………..17

2.6     Endogenous energy losses ………………………………………………………17

2.7     Nitrogen retention …………………………………………………………18

2.8     Feedstuffs under investigation ……………………………………………….19

2.8.1  Rice milling waste………………………………………………………….19

2.8.2  Maize pap waste ……………………………………………………………19

2.9     Feed conversion ratio ………………………………………………………20

CHAPTER THREE: Materials and methods

3.1     Location ……………………………………………………………………22

3.2     Materials ……………………………………………………………………22

3.3     Experimental birds and management ………………………………………23

3.3.1  Experiment I………………………………………………………………..24

3.3.2  Experiment II ………………………………………………………………24

3.3.3  Experimental diets …………………………………………………………25

3.4     Experimental procedure ……………………………………………………29

3.5     Excreta collection …………………………………………………………….30

3.6     Gross energy determination………………………………………………………………..31

3.7     Nutrient retention study……………………………………………………32

3.8     Carcass and organ evaluation ………………………………………………33

3.9.1  Data collection and parameters measured ………………………………………33

3.9.2  Parameters calculated ………………………………………………………33

3.10   Proximate analysis of the diets and excreta …………………………………..35

3.11   Statistical analysis………………………………………………………….35

CHAPTER FOUR: Results and discussion

4.1     Results………………………………………………………………………37

4.1.1  Metabolizable energy contents of maize pap and rice milling waste………37

4.1.2  Growth performance of broilers fed graded levels of MPW……38

4.1.3  Apparent nutrient retention of broilers fed graded levels of MPW……………39

4.1.4  Carcass and organ characteristics of broilers fed graded levels of MPW….39

4.1.5 Growth performance of broilers fed graded levels of RMW……………………..41

4.1.6  Apparent nutrient retention of broilers fed graded levels of RMW…………..42

4.1.7  Carcass and organ characteristics of broilers fed graded levels of RMW…..42

4.2     Discussion…………………………………………………………………..44

4.2.1  Apparent metabolizable energy and true metabolizable energy….…44

4.2.2  Live weight gain……………………………………………………………44

4.2.3  Feed intake…………………………………………………………………45

4.2.4  Feed conversion ratio………………………………………………………45

  • Feed cost per weight gain…………………………………………………..46

4.2.6  Proximate analysis………………………………………………………….47

4.2.7  Apparent nutrient retention………………………………………………..47

4.2.8  Carcass and organ evaluation………………………………………………48

CHAPTER FIVE: Conclusion and recommendation

5.1     Conclusion ………………………………………………………………………49

5.2     Recommendation ……………………………………………………………..50

References ………………………………………………………………………..51

LIST OF TABLES

Table                                                                                                                   page

1a. Percentage composition of the starter diets containing MPW …………26

1b. Percentage composition of the finisher diets containing MPW ……..27

2a. Percentage composition of the starter diets containing RMW ….28

2b. Percentage composition of the finisher diets containing RMW ……..29

3.  Composition of vitamin and mineral premix…………………………….…….30

4.  Quantity of excreta voided per bird within the period of 30 hours …32

5.  Gross energy of the feedstuffs …………………………………………………33

6.  Gross energy, apparent metabolizable energy and true metabolizable energy…37

7.  Performance of broiler birds fed varying levels of MPW for eight weeks … ……………… ………………………………………… ………………………… ….38

8.  Effect of diets containing MPW on nutrient retention of broiler birds ……… ………………………………………… ………………………………………… …39

9.  Effect of dietary levels of MPW on carcass quality and organ characteristics of     broiler birds…………………………40

10. Proximate composition of starter and finisher diets containing MPW…………..40

11. Performance of broiler birds fed varying levels of RMW for eight weeks … ………………………………………… ………………………………………… ..41

12. Effect of diets containing RWW on nutrient retention of broiler birds …… ………………………………………… ………………………………………… …..42

13. Effect of dietary levels of RMW on carcass quality and organ characteristics of   broiler birds…… ……………………………43

14. Proximate composition of starter and finisher diets containing RMW.…… ………………………………………… ………………………………………… …..43

ABSTRACT

An experiment was conducted to determine the metabolizable energy of maize pap waste (MPW) and rice milling waste (RMW) using adult male broiler birds. Eighteen male adult broiler birds were used in the experiment. Eight birds were assigned to each of the feedstuff with two birds left unfed which served as the negative control. Each of the samples was ground, made into slurry and force-fed to sixteen 10-week old finisher broiler birds that had been starved for 30 hours. The droppings were collected quantitatively, dried and the gross energy was determined in a bomb calorimeter. The results show that the gross energy, apparent and true metabolizable energy of MPW (4.01, 2.60 and 3.03kcal/g) were significantly (P<0.05) higher than those of RMW (2.94, 0.8 and 1.09kcal/g), respectively. Prior to the determination of the true metabolizable energy, two experiments were conducted concurrently to evaluate the effects of feeding graded levels of MPW and RMW on the performance of broiler birds. A total of one hundred and forty-four 2-week old broiler birds with average weight of 330g were randomly allocated to four dietary treatments containing 0, 10, 20 and 30% MPW and RMW, respectively. The effect of treatments on the final body weight (FBW), average daily weight gain (DWG), average daily feed intake (DFI), feed conversion ratio (FCR), feed cost per weight gain FC/WG, carcass quality and organ characteristics were determined. Differences in DFI and ADG were not significant (P>0.05). Similarly, the FBW of broilers fed the 0, 10, 20 and 30% MPW (3520g, 3470g and 3500g, respectively) and RMW (3345g, 3329g, 3337g and 3330g, respectively) diets were found to be comparable (P>0.05) within the different groups. However, feed cost per unit weight gain decreased significantly with increasing levels of MPW and RMW in the diets. The lower feed cost per kilogram meat produced on 30% MPW and RMW diets suggest that the wastes are economically viable alternative energy sources. It was concluded that at up to the 30% inclusion level of MPW and RMW in the diets, FBW and FCR were not significantly affected (P>0.05). However, the financial return was positively affected (P<0.05) at this level.

CHAPTER ONE

INTRODUCTION

1.1     Background

Livestock industry in Nigeria is ridden with myriad of problems, which have resulted to a gross shortage of meat and other animal products (Nworgu, 2002). The animal protein intake shortages in Nigeria observed in the early 1970s has progressively worsened till date. The protein intake of an average Nigerian is about 53.8g with only 6.0 – 8.4g per caput per day of animal origin (Egbunike, 1997). CBN (2003) revealed that North America, Western and Eastern European countries consume 66, 39 and 33g of animal protein per head per day respectively; while an average Nigerian consumes 7.5g which is below the recommended level of 27g per caput per day. The sub-optimal consumption of animal protein by a large percentage of Nigerian population has challenged not only livestock farmers, but also researchers and policy makers.

Poultry industry is one of the major sources of animal protein and offers the potential for bridging the protein deficiency gap existing in the country. However, the inadequate supply of several grains and protein concentrates for poultry feeding and the keen competition between man and animal for same have become the major obstacle in poultry industry development in Nigeria (PAN, 1985; Ologhobo, 1992). Feed constitute the dominant input in animal production ranging from 65-75% of the total cost of production. Similarly, feed ingredients account for over 90% of compound feed industry. Therefore, the relationship between feed ingredient and animal product output is both direct and obvious. To depend on alternative sources of ingredients, especially when it encourages a shift to ingredients for which there is less competition, may help if the later is cheap and sufficiently available (Oluyemi and Roberts, 1979). The future of efficient and profitable poultry production would, therefore, depend on finding cheaper and alternative energy and protein sources to conventional protein and energy feed ingredients.

Recently, much effort is being made to find the possibilities of utilizing agro-industrial by-products in poultry nutrition (Henuk and Dingle, 2003). This could lead to the reduction in the use of conventional feed ingredients such as maize, soybean, sorghum, groundnut, wheat etc (El Boushy and Van der Poel, 2000) and help reduce pollution problems, decrease feed cost and increase livestock production.

Agro-industrial by-products in Nigeria vary from primary processing of farm produce wastes to wastes from agro-allied industries. Some of these wastes are left unutilized, which often cause environmental pollution and hazard. Those that are utilized do not have their full potentials harnessed. Agro-industrial by-products which can be of tremendous use in the livestock industry for feeding animals include maize pap waste and rice milling waste etc.

Since energy is one of the most expensive segments of a poultry ration, accurate knowledge of the available energy content of feedstuffs is necessary to formulate the most economical least-cost rations and to achieve profitable production. Supplying adequate energy to birds is one of the most important aspects of successful management program. It is by knowing and meeting the nutrient requirements of the bird that their full genetic potentialities can be realized.

 Apparent metabolizable energy (AME) is the most widely used method for evaluating poultry feedstuffs for available energy. However, since Sibbald (1976) developed a bioassay for true metabolizable energy (TME), a considerable amount of research has been conducted to investigate the assay’s applicability. Sibbald’s method has several advantages over the previous AME assays. It is simple, rapid, and inexpensive. Besides its reported flexibility, reproducibility, and data quality (Sibbald, 1976), the TME assay can be extended to measure bioavailable amino acids (Likuski and Dorrel, 1979; Sibbald, 1979) and lipids (Sibbald and Kramer, 1978) in feedstuffs.

Although literature is replete of the importance of energy in poultry nutrition, there are two feedstuffs of regional interest that require evaluation for their nutrient composition especially their energy content. For such feedstuffs, knowledge of their available energy will enhance their usefulness in poultry feeding.

1.2     Statement of the Problem

DETERMINATION OF THE TRUE METABOLIZABLE ENERGY OF SOME NON-CONVENTIONAL AGRO-INDUSTRIAL BY-PRODUCTS