ABSTRACT
Two feeding trials were conducted to evaluate the effect of sweet potato and sweet potato peel
meals on the growth and laying performance of Japanese quails (Coturnix coturnix japonica).
One thousand Five hundred and six Japanese quails were used for the study. In experiment 1,
three hundred mixed sexes of 2 weeks old Japanese quails (mean weight 32.00g) were fed the
different diets of sweet potato meal for a period of 28 days for the grower phase and two
hundred and twenty eight female 7 weeks old Japanese quail birds ( mean weight 137.00g)
were fed for 112 days for the laying phase. The birds were assigned to four dietary treatments
each (0, 10, 20, 30%) of sweet potato meal consisting of 75 grower quails per treatment with
three replicates of 25 birds at the grower phase and 57 hens per treatment with three replicates
of 19 birds at laying phase. Water and feed were supplied ad libitum. During grower phase,
higher final body weight (141.47g) of the Japanese quails was achieved in quail birds fed diets
containing 10% sweet potato meal, this was followed by the quail birds fed 0% sweet potato
meal (141.28g) while the least final body weight (134.80 g) was obtained in the quail birds fed
30% sweet potato diet. The feed conversion ratio showed no significant (P < 0.05) differences
across the entire treatment groups for sweet potato meal. Higher carcass weight (101.52g) of
the quails was achieved in birds fed diets containing 10% sweet potato meal. Quails fed diets
containing 10% sweet potato meal had better apparent digestibility of nutrients compared to
birds fed other diets. Feed cost analysis during grower phase revealed that birds fed diets
containing 30% sweet potato meal (( 304.67) had better feed cost than birds on other diets.
The result on laying performance and egg characteristics showed significant (P < 0.05)
differences in birds fed sweet potato meal. Hen-day egg production of quails fed 10% sweet
potato meal diets (55.71) was significantly (P < 0.05) higher than those of birds fed the other
diets. Peak egg production values of birds fed 10% sweet potato meal (83.33 days) was
statistically the same with birds fed 0% sweet potato diets (82.31days). There was no mortality
recorded during the grower and laying phase. In experiment 2, three hundred mixed sexes of 2
weeks old Japanese quails (mean weight 32.00g) were fed the different diets of sweet potato
peels meal for a period of 28 days for the grower phase and two hundred and twenty eight
female 7weeks old Japanese quail birds ( mean weight 137.00g) were fed for 112 days for the
laying phase. The birds were assigned to four dietary treatments each (0, 10, 20, 30%) of sweet
potato peel meal consisting of 75 grower quails per treatment with three replicates of 25 birds
at the grower phase and 57 hens per treatment with three replicates of 19 birds at laying phase.
Water and feed were supplied ad libitum. At grower phase, higher final body weight (141.33g)
of the Japanese quails was achieved in quail birds fed diets containing 10% sweet potato peel
meal, this was followed by the quail birds fed 0% sweet potato peels meal (141.28g) while the
least final body weight (132.32 g) was obtained in the quails fed diets containing 30% sweet
potato peel meal. Quail birds fed 10% sweet potato peel meal performed significantly (P <
0.05) better in feed conversion ratio. Quails on 0% sweet potato peel meal (control) had higher
carcass weight (98.80) compared to other dietary treatment (P < 0.05). Birds on 10% sweet
potato peel meal performed better than birds on other diets on apparent crude protein
digestibility. Feed cost analysis during grower phase revealed that birds fed 30% sweet potato
peel meal had better feed cost ( 247.08) than birds fed other diets. The result on laying
performance and egg characteristics showed significant (P < 0.05) differences in birds fed
sweet potato peel meal. Hen-day egg production of quails fed 10% sweet potato peel meal diets
(52.43) was significantly (P < 0.05) higher than those of birds on the other diets. Peak egg
viii
production values of birds fed 10% sweet potato peel meal (82.31days) was statistically similar
with birds fed 0% sweet potato diets (82.31). There was no mortality recorded during the
grower and laying phase. Inclusion of sweet potato and sweet potato peel meals in the diets of
Japanese quails did not result in any detrimental effect on overall performance. Thus
substituting maize with sweet potato meal at 10% inclusion and sweet potato peel meal at 10%
inclusion in Japanese quails diet resulted in enhanced growth and egg production performance
at the least cost. At the growing phase, diets containing sweet potato meal at 10, 20 and 30%
levels of inclusion reduced cost of production by 1.97%( 0.62), 3.21% ( 1.01) and 5.35% (
1.68) respectively while diets containing 10 and 30% sweet potato peel meal reduced the cost
of production by 59.04% ( 18.55) and 66.58% ( 66.58) respectively.
TABLE OF CONTENTS
Cover page
Fly page
Title page……………………………………………………………………………………………………..i
Declaration…………………………………………………………………………………………………..ii
Certification……………………………………………………….……………………………………..iii
Dedication……………………………………………………………………………………………………..iv
Acknowledgements………………………………………………………………………………………….v
Abstract…………………………………………………………………………………………………….vii
Table of contents…………………………………………………………………………………………ix
List of tables……………………………………………………………………………………………….xiv
CHAPTER ONE ………………………………………………………………………………………………………………………. 1
1.0 INTRODUCTION ……………………………………………………………………………………………………… 1
1.1 Background of the Study………..…………………………………………………….……… 1
1.2 Justification …………………………………………………………………………..………..4
1.3 Objectives of the study…………………………………………………………………………4
1.4 Hypotheses……………………………………………………………………………………..5
CHAPTER TWO…………………………………………………………………………………………7
2.0 LITERATURE REVIEW………………………………………………………………………7
2.1 Sweet Potato ( Ipomoea batatas) ….…………………………………………………………..7
2.2 Origin and Distribution of Sweet Potato ….…………………………………………………..7
2.3 Global situation of Sweet Potato production .….……………………………………………..8
2.4 Processing Techniques of Sweet potato ……………………………………………………..10
2.5 Chemical Composition of Sweet Potato …………………………………………………….11
2.5.1 Carbohydrates in Sweet Potato………………………………………………………………..11
x
2.5.2 Protein Content of Sweet Potato………………………………………………………………13
2.5.3 Lipid Content of Sweet Potato ……………………………………………………………….16
2.5.4 Vitamin Content of Sweet Potato.……………………………………………………………17
2.5.5 Mineral Content of Sweet Potato……………………………………………………………..19
2.6 Anti-nutritional Factors in Sweet Potato……………………………………………………..19
2.6.1. Trypsin Inhibitors in Sweet Potato….…………………………………………………………22
2.6.2 Oxalate in Sweet Potato….……………………………………………………………………24
2.6.3 Chemical and Phytochemicals in Sweet Potato……….…….……….……………………….24
2.7 Uses of Sweet Potato in Poultry Feeding………………….………………………………….27
2.8 Sweet Potato Peel As Source of Dietary Fibre …..…………………………………………..31
2.9 Miscellaneous Uses of Potato Peels….………………………………………………………32
2.10 Japanese quail (Coturnix coturnix)…………..……………………………………………….33
2.10.1 History of Japanese Quails (Coturnix coturnix)………………………………………………33
2.10.2 Japanese quail coturnix grower………………………………………………………………35
2.10.3 Nutritional Requirements of Japanese Quails………………………………………………..36
2.10.3.1 Quail feeding…………………………………………………………………………………36
2.10.3.2 Protein……….……………………………………………………………………………….37
2.10.3.3 Energy ……………………………………………………………………………………….38
2.10.3.4 Vitamin ………………………………………………………………………………………39
2.10.3.5 Minerals ………………………………………………………………………………..…44
2.10.3.5.1 Calcium and Phosphorus ………..………………………………………………………….45
2.10.3.5.2 Magnesium …..……………………………………………………………………………..45
2.10.3.5.3 Manganese ……. …………………………………………………………………………46
2.10.3.5.4 Salt (Sodium Chloride) ……..………………………………………………………………48
2.10.3.5.5 Iron, Copper and Cobalt ……..…………………………………………………………….46
2.10.3.5.6 Selenium …………..……………………………………………………………………….47
2.10.3.5.7 Zinc …..…………………………………………………………………………………….48
xi
2.10.4 Performance of Japanese Quails ……… ………………………………………………….48
2.10.5 Haematological Indices of Quails ………………………………………………………….49
2.10.6 Carcass Characteristics of Quails ….… ……………………………………………………51
2.10.7 Effect of Processing of Ingredients on Carcass Characteristics of Quails…….… …………51
CHAPTER THREE.…………………………………………………………………………………….53
3.0 MATERIALS AND METHODS ….…….. ………………………………………………..53
3.1 Experimental Site ………..…………………………………………………………………..53
3.2 Source of Experimental Birds ………..………………………………………………………53
3.3 Source and Processing of Sweet Potato and Sweet Potato Peels…………………………….53
3.4 Laboratory Analysis…………………………………………… ………..………………….54
3.5 Experiment 1a: Growth Performance of Japanese Quails Fed Diet Containing varying Levels
of Sweet Potato Meal (2-6 weeks) …….. ………………………………………………….55
3.5.1 Experimental Diets for Grower Japanese Quails ………..……………………………………55
3.5.2 Experimental Design and Management of Birds (2-6 weeks) ……….………………………55
3.5.3 Determination of Haematological and Biochemical Parameters….. ………..….……………57
3.5.4 Digestibility Trial…………………………………………………………………………….57
3.5.5 Carcass Analysis ………..……………………………………………………………………58
3.5.6 Statistical Analysis ………. …………………………………………………………………59
3.5.7 Cost Benefit Analysis ……… ………………………………………………………………59
3.6 Experiment 1b: Laying Performance of Japanese Quails Fed Diet Containing Varying Levels
of Sweet Potato Meal (7-20weeks) ……….…………………………………………………….59
3.6.1 Experimental Diets for Laying Japanese Quail Hens …………………………………………59
3.6.2 Determination of Proximate Composition of Experimental Diets ……………………………60
3.6.3 Experimental Design and Management of Birds (7-16weeks) ………………………………60
3.6.4 Determination of Egg Quality Parameters……………………………………………………..62
3.6.5 Statistical Analysis ……………………………………………………………………………65
3.7 Experiment 2a: Growth Performance of Japanese Quails Fed Diet Containing varying Levels
of Sweet Potato Peel Meal (2-6 weeks) … .……… ………………………………………….65
xii
3.7.1 Experimental Diets for Grower Japanese Quails ………..…………………………………… .65
3.7.2 Determination of the Proximate Composition of Experimental Diets. …… ………………..66
3.7.3 Experimental Design and Management of Birds (2-6weeks) ………..………………………66
3.7.4 Determination of Haematological and Biochemical Parameters……………..….…………….66
3.7.5 Digestibility Trial ………..……………………………………………………………………66
3.7.6 Carcass Analysis ………..……………………………………………………………………66
3.7.7 Statistical Analysis ……………………………………………………………………………66
3.7.8 Cost Benefit Analysis …………………………………………………………………………66
3.8 Experiment 2b: Laying Performance of Japanese Quails Fed Diet Containing Varying Levels
of Sweet Potato Meal Peel (7-20weeks) ……………………………………………………….68
3.8.1 Experimental Diets for Grower Japanese Quails ………………………………………………68
3.8.2 Determination of Proximate Composition of Experimental Diets.……………………………68
3.8.3 Experimental Design and Management of Birds (2-6weeks) …………………………………68
3.8.4 Determination of Egg Quality Parameter ……………………………………………………..68
3.8.5 Statistical Analysis ……………………………………………………………………………68
CHAPTER FOUR ………………………………………………………………………………………70
4.0 RESULTS…………………………………………………………………………………… 70
4.0 Proximate Composition of Sweet Potato Meal…………………………………………………70
4.2 Experiment 1a: Effect of Diets Containing Varying Levels of Sweet Potato Meal on Growth
Performance, Digestibility, Haematological Parameters, Carcass Characteristics and Cost
Benefits Analysis of Grower Japanese Quails …….…….…….………………………………70
4.3 Experiment 1b: Effect of Diets Containing Varying Levels of Sweet Potato Meal on Laying
Performance and Egg Quality Characteristics Japanese Quails…………………………..……78
4.4 Proximate Composition of Sweet Potato Meal…………………………………………………84
4.5 Experiment 2a: Effect of Diets Containing Varying Levels of Sweet Potato Peel Meal on
Growth Performance, Digestibility, Haematological Parameters, Carcass Characteristics and
Cost Benefits Analysis of Grower Japanese Quails …….…….………………………………84
4.6 Experiment 2b: Effect of Diets Containing Varying Levels of Sweet Potato Peel Meal on
xiii
Laying Performance and Egg Quality Characteristics Japanese Quails……… ………..……93
CHAPTER FIVE ………………………………………………………………………………………100
5.0 DISCUSSION ………………….……………………………………….…………………….100
5.1 Proximate Composition of Sweet Potato and Sweet Potato Peel Meals ….………………….100
5.2 Effect of Diets Containing Varying Levels of Sweet Potato Meal on Growth Performance, Cost
Benefits Analysis, Nutrient Digestibility, Haematological Parameter and Carcass
Characteristics of Grower Japanese Quails (2-6weeks) ……………………………………….101
5.3 Effect of Diets Containing Varying Levels of Sweet Potato Meal on Laying Performance and
Egg Quality Characteristics of Japanese Quail Hens (7-20weeks).…………………………..105
5.4 Effect of Diets Containing Varying Levels of Sweet Potato Peel Meal on Growth Performance,
Cost Benefits Analysis, Nutrient Digestibility, Haematological Parameter and Carcass
Characteristics of Grower Japanese Quails (2-6weeks) …….………………………………….108
5.5 Effect of Diets Containing Varying Levels of Sweet Potato Peel Meal on Laying Performance
and Egg Quality Characteristics Japanese Quail Hens (7-20weeks)…………………………..112
CHAPTER SIX…………………………………………………………………………………………116
6.0 SUMMARY, CONCLUSION AND RECOMMENDATION ……………………………..116
6.1 Summary……………………………………………………………………………………116
6.2 Conclusion .……………………………………………………………………………….. 117
6.3 Recommendations………………………………………………………………………… 117
REFERENCES…………………………………………………………………………………………118
xiv
CHAPTER ONE
INTRODUCTION
1.1 Background to the Study
Poultry is an important source of protein to the ever-expanding human population. The cost of
feed has been identified by farmers as the major constraint in poultry production (Munyawu et
al., 1998). The poultry producers have experienced a rise in the cost of production due to the
increasing cost of feed. The cost of maize which makes 65 % of the current poultry feeds is
very high (Scott, 1995; Mutetwa, 1996). Maize has a lot of industrial and domestic uses, such
as bio-fuel, brewing, starch industries and for human food. However, inadequate production of
this grain and the intense competition for maize between man, industries and livestock has
made poultry rations to be expensive. This situation has forced poultry farms and feed millers
to search for alternative feed ingredients which are available in large quantities, cheaper and
can substitute for the scarce and expensive maize. Some of these feed alternatives are sweet
potato (Ipomoea batatas) and their peels, which have great potentials as energy sources in
poultry nutrition.
Prices of poultry products, especially eggs keep rising as a result of the rise in the costs of feed,
which constitute between 60-80% of the total production costs (Nuhu et al., 2008). The
conventional energy feed sources constitute between 40-65% of formulated poultry diets and
have high price tags as a result of their numerous alternative uses (Afolayan, 2010). Among
these sources, maize is the most widely employed for poultry feed formulation (Vantsawa,
2001; Afolayan et al., 2012). In order to step down the problem of high and unstable price
situation and save the poultry industry from collapse, there is need to broaden the energy
2
source base by assessing unconventional feedstuffs (Afolayan et al., 2012). Maize and sweet
potato have comparable metabolizable energy values of 14.5 and 14.8 Kcal respectively
(Woolfe, 1992). The digestibility of sweet potato carbohydrate fraction is reported to be above
90% (Ravindran, 1995). However, the level of starch decreases with period of storage and
instead the level of reducing sugars, total sugars and total dextrins increase (Woolfe, 1992).
Sweet potatoes have also been reported to exhibit trypsin inhibitor activity ranging from 20 to
90 % inhibition (Woolfe, 1992). However, Ravindran (1995) reported that trypsin inhibitor
levels present in sweet potato tubers are low and should not be a cause for concern under
practical situations. A study carried out in Nigeria recommended 27 and 30 % levels of sweet
potato in the starter and finisher diets of poultry, respectively (Agwunobi, 1999). However,
Woolfe (1992) reported having replaced 50 to 75% of maize in poultry feed with dried sweet
potato flour without adverse effects on the growth of broilers.
The pollution caused by the potato peels as waste product has become an environmental
concern. It poses a lot of problems for disposal especially during the wet season as it decays
easily and pollutes the environment. Potato is processed into value added products by fast food
industries. Sweet Potato is usually peeled during processing either by steam, lye or abrasive
peeling methods depending on the type of products desired. However, large quantities of peels
are generated which represent a severe disposal problem with increasing awareness and aims
of minimizing environmental impact and sustainability (Schieber et al., 2009). Potato peels
contain some nutritionally and pharmacologically interesting compounds such as polyphenols
and glycoalkaloids which may serve as natural antioxidants and precursors for steroid
hormones (Schieber et al., 2009). Potatoes are good sources of energy due to their high
carbohydrate content. They also contain some protein and are rich in organic micronutrient
such as Vitamin C, B vitamins and an appreciable level of minerals. Sweet potatoes are also a
3
very valuable source of feed for all classes of livestock (Woolfe, 1992). The tubers are relished
by pigs and cattle. In 2007, half of the sweet potato tuber production went into animal feeding
in United State of America (USA) and United Kingdom (Lebot, 2009; Chittaranjan, 2007).
Sweet potatoes can be used on-farm or as an ingredient in commercial compound feeds (Scott,
1992; Gupta et al., 2009). The peels, which are the major portion of processing waste,
represent a severe disposal problem to the industry since wet peels are prone to rapid microbial
spoilage. Potato peels though a waste product of the food industry is a source of high value
compounds (Schieber et al, 2001).
Japanese quails (Coturnix coturnix japonica) are small-sized, early maturing, hardy and
prolific birds (Robbins, 1981). They come into egg production between the 5th and 6th week
of life, but adult plumage is not attained until the 12th week of age (Martins et al., 1998). The
eggs are small, mottled and weigh between 10 and 13g each (Edache et al., 2003a; Musa et al.,
2008) with egg fertility and hatchability levels of 90% and 65% respectively (Edache et al.,
2003b). The meat and eggs are low in body fat and cholesterol (Schwartz and Allen, 1981)
which is of public health significance. Persons prone to high blood pressure and related
diseases could consume these products with less risk. Crude protein diet content of 20% has
been recommended for optimum egg production in Japanese quails (Edache et al., 2003a;
Akpa et al., 2008). The usual high inclusion of maize in poultry diets translates into high cost
of feed because of seasonality of production and competition for maize by man (Agbede et al.,
2002). According to Bamgbose et al. (2004) maize accounts for about 45 to 55% of poultry
feed. This necessitates the need to replace maize either partially or totally in poultry diets to
reduce overall cost. Increasing use of alternatives to maize has been recommended (Ani, 2007;
Ani and Omeje, 2007; Obikaonu and Udedibie, 2007).
Currently, very few information exist on the use of sweet potato and the peels in Japanese quail
4
diets in Nigeria.
1.2 Justification
The Nigerian poultry industry is faced with a lot of problems that have resulted to a gross
shortage of meat to meet the population challenge in the country and there is acute shortage of
animal protein in the diet of an average Nigerian (FAO, 2006). This is due to the high cost of
conventional protein and energy concentrates, increasing competition between man, industries
and livestock for the available grains, price fluctuations and unavailability of the feed
ingredients for the formulation of animal feeds (Duru and Dafwang, 2010). Profit
maximization cannot be attained unless the birds are fed diets at lowest costs. There is need to
search for non-conventional feed resources that are cost-effective, non-toxic and readily
available and alternative sources of energy concentrate. Sweet potato and the peels can be a
good alternative source of energy in poultry ration.
The main aim of this research is to evaluate the effect of Sweet potato and its peels as
alternative energy sources on the growth and laying performance of Japanese quails.
1.3 Objectives of the study
The objectives of the study are to investigate: The effect of:
i. diets containing varying levels of Sweet Potato and Sweet Potato Peel Meals on
growth performance of Japanese quails.
ii. diets containing varying levels of Sweet Potato and Sweet Potato Peel Meals on
nutrient digestibility, carcass characteristics, haematological and biochemical
parameters of Japanese quails.
iii. diets containing varying levels of Sweet Potato and Sweet Potato Peel Meals on laying
performance of Japanese quails.
5
iv. diets containing varying levels of Sweet Potato and Sweet Potato Peel Meals on the
external and internal egg quality characteristics of Japanese quails.
v. Using varying levels of Sweet Potato and Sweet Potato Peel Meals in Japanese quail
rations on the economics of Japanese quail production.
1.4 HYPOTHESES
Experiment 1
Null Hypothesis (Ho): Diets containing varying levels of Sweet Potato Meal have no effect on
growth performance, Carcass characteristics, Nutrient digestibility, Haematological and
Biochemical parameters of Japanese quails.
Diets containing varying levels of Sweet Potato Meal have no effect on laying performance of
Japanese quails.
Diets containing varying levels of Sweet Potato Meal have no effect on the external and
internal egg quality characteristics of Japanese quail eggs.
Alternative Hypothesis (HA): Diets containing varying levels of Sweet Potato Meal have
effect on growth performance, Carcass characteristics, Nutrient digestibility, Haematological
and Biochemical parameters of Japanese quails.
Diets containing varying levels of Sweet Potato Meal have no effect on laying performance of
Japanese quails.
Diets containing varying levels of Sweet Potato Meal have effect on the external and internal
egg quality characteristics of Japanese quail eggs.
6
Experiment 2
Null Hypothesis (Ho): Diets containing varying levels of Sweet Potato Peel Meal have no
effect on growth performance, Carcass characteristics, Nutrient digestibility, Haematological
and Biochemical parameters of Japanese quails.
Diets containing varying levels of Sweet Potato Peel Meal have no effect on laying
performance of Japanese quails.
Diets containing varying levels of Sweet Potato Peel Meal have effect on the external and
internal egg quality characteristics of Japanese quail eggs.
Alternative Hypothesis (HA): Diets containing varying levels of Sweet Potato Peel Meal have
effect on growth performance, Carcass characteristics, Nutrient digestibility, Haematological
and Biochemical parameters of Japanese quails.
Diets containing varying levels of Sweet Potato Peel Meal have effect on laying performance
of Japanese quails.
Diets containing varying levels of Sweet Potato Peel Meal have effect on the external and
internal egg quality characteristics of Japanese quail eggs.
7
IF YOU CAN'T FIND YOUR TOPIC, CLICK HERE TO HIRE A WRITER»
