Protein and Energy Requirements of African Giant Land Snail (Achatina Achatina).
ABSTRACT
A 16-week study was conducted to investigate the effect of dietary protein and energy levels on the growth performance of African giant land snail (Achatina achatina).
Two hundred and forty eight weeks old African giant land snails were used for the study. The snails were randomly divided into 16 groups of 15 snails each.
The groups were randomly assigned to 16 diets in a 4 x 4 factorial arrangement involving four levels ((18%, 20%, 22%, and 24%) of protein and fourenergy levels (2.6, 2.8, 3.0 and 3.2Mcal/kg ME).
Each treatment was replicated 3 times with 5 snails per replicate. Results showed that while body weight gain, feed intake, protein efficiency ratio and carcass yield were significantly (P < 0.05) increased at the 24%CP and 3.2Mcal/Kg ME levels, FCR and cost of feed per kg weight gain were decreased(P < 0.05).
There were significant (P < 0.05) interactions between protein and energy levels on final body weight, average daily weight gain, average daily feed intake, feed conversion ratio, protein efficiency ratio, shell length, shell width, feed cost per kg weight gain and carcass yield.
Feed intake was significantly (P < 0.05) decreased at the 3.0 Mcal/kg ME and 18%CP levels, and at the 3.2 Mcal/kg ME and 18% CP levels; FCR values were decreased(P < 0.05) at the 3.0 Mcal/kg ME and 24 %CP levels, and at the 3.2 Mcal/kg ME and 24% CP levels.
PER was enhanced (P < 0.05) at the 24 %CP level and at the 2.80 Mcal/kg, 3.0 Mcal/kg and 3.2 Mcal/kg energy levels; shell length was enhanced (P < 0.05) at the 3.0 Mcal/kg ME and 22% CP levels, and at 10 the 24% CP and 3.2 Mcal/kg ME levels.
shell width was enhanced (P < 0.05) at the 3.0 Mcal/kg ME and 24% CP levels, and at the 24% CP and 3.2 Mcal/kg ME levels. Feed cost per kg weight gain was significantly (P < 0.05) reduced at the 24% CP and 3.2 Mcal/kg ME levels.
The results obtained in the present study show that the dietary protein and energy levels of 24% and 3.2Mcal/kg ME are adequate for the growth of African giant land snails (Achatina achatina) in the humid tropics.
TABLE OF CONTENTS
Title page – – – – – – – – – i
Certification – – – – – – – – ii
Dedication – – – – – – – – – – iii
Acknowledgement – – – – – – – iv
Table of contents – – – – – – – – vi
List of tables – – – – – – – – vii
List of figures – – – – – – – – viii
Abstract – – – – – – – – – x
CHAPTER ONE: INTRODUCTION – – – –
1.1 Background – – – – – – – – 1
1.2 Statement of Problem – – – – – – 2
1.3 Objectives – – – – – – – – 3
1.4 Justification of the Study – – – – – – 4
CHAPTER TWO: LITERATURE REVIEW – – – – 5
2.1 Classification of the edible land snails – – – 6
2.2 Morphological and anatomical characteristics – – 6
2.3 Common edible land snails of Africa origin – – – 7
2.4 Common edible snails in Europe – – – – 9
2.5 Differences between the three african giant snails – – 10
2.6 Life cycle development of snail – – – – 11
2.7 Reproduction – – – – – – – 12
2.8 Snail rearing – – – – – – – 14
2.9 Selection of breeding stock – – – – – 16
2.10 Feeds and feeding – – – – – – 16
2.11 Problems associated with snail farming – – – 21
2.12 Special behavioural instincts of the snail – – – 23
2.13 Nutritional and economic importance of snails – – 24
2.14 Snails in international market – – – – – 26
CHAPTER THREE: MATERIAL AND METHODS 28
3.1 Location of study – – – – – – – 28
3.2 Materials and Duration of study – – – – 28
3.3 Experimental diets and design – – – – – 29
3.4 Management of Experimental animals – – – 31
3.5 Parameters determined – – – – – – 32
3.6 Proximate and Statistical Analysis – – – – 33
CHAPTER FOUR: RESULTS – – – – – 34
4.1 Body weight – – – – – – – 34
4.2 Feed intake – – – – – – – – 34
4.3 Feed conversion ratio – – – – – – 35
4.4 Protein efficiency ratio – – – – – – 35
4.5 Shell length – – – – – – – – 36
4.6 Shell width – – – – – – – – 36
4.7 Carcass Analysis – – – – – – – 36
4.8 Feed cost – – – – – – – – 41
CHAPTER FIVE: DISCUSSION 43
5.1 Discussion – – – – – – – – 43
5.2 Summary, conclusion and recommendation – – – 48
REFERENCES – – – – – – – – 50
APPENDIX I – – – – – – – – 58
APPENDIX II – – – – – – – – 59
INTRODUCTION
1.1 BACKGROUND
The importance of protein in the diet of man cannot be over-emphasized. Protein is required for normal growth and repair of the body tissues. It is the principal constituent of the organs of the animals’ body. Protein can be of plant or animal origin.
Most plant protein is deficient in one amino acid or the other and may be associated with one anti- nutritional factor or another. Soyabean for instance is a vegetable protein source that contains trypsin inhibitor and is deficient in methionine.
Animal protein is of high biological value and possesses all the essential amino acids in desirable quantities. The sources of animal protein include macro and micro livestock.
The macro livestock are the conventional big animals such as sheep, goat, cattle, etc. However, the cost of production of macro livestock in term of housing, feeding, space and disease control is high. Micro livestock are excellent and cheaper sources of animal proteins (Akinnusi, 1998; NRC, 1991).
The term micro livestock refers to a group of livestock associated with small body size, moderate nutrition and management (Oji, 2000).
It includes snails, rabbits and cane rat, among others. Snails are invertebrate, shell bearing animals that are passive or inactive during the day, but very active in the night, at dusk or when it rains. They are usually found in cool environment (Segun 1975; FAO, 1986).
Snail meat tastes good and it is also consumer friendly. When eaten, it serves as a special delicacy in the diet.
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Ajayi, S. S; Tewe, O. O; Moriarity and Awesu, M. O (1978) observation on the biological and nutritive value of the African giant land snail (A. marginata). East Africa wildlife journal (16), 85 – 95.
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