ABSTRACT
The study was undertaken to compare and evaluate growth performance, conformation and morphological traits of three commercial strains of broiler chicken. A total of 315 day old chicks of three broiler strains (105 from each strain) consisting of NAPRI-X, Marshall and Ross strains, respectively were used in this experiment. Computed indices comprising of Daily feed intake (DFI), weekly weight gain, percentage mortality (MTLY) and feed conversion ratio (FCR) as growth traits; whereas the conformation traits which include Neck length (NEL), back length (BKL), thigh length (THL), shank length (SHL), breast width (BRW), body length (BDL) and wing length (WNL) were obtained. Traits consisting of ocular length (OCL), ocular width (OCW), comb length (CBL), comb width (CBW), beak length (BEL), ear lobe length (ELL), ear lobe width (ELW), wattle length (WTL) and wattle width (WTW) were the morphological traits. Descriptive statistics, correlation, regression and principal component analyses (PCA) were carried out. Results for comparative growth performance, conformation and morphological traits among the three strains at 4 and 8 weeks of age showed that Marshall strain had significantly (P<0.05) higher mean values, except for WTL and WTH in which NAPRI-X breed had the highest values at 8 weeks. However, no significant (P>0.05) differences were observed among the three strains for MTLTY, FCR, BDL, WNL, ELL and ELW, respectively, at 8 week and also MTLTY at 4 week. Correlations among growth traits revealed positive and perfect correlations between FBW, DWG, TWG, DFI and TFI in all the three strains at 4 weeks of age. At 8 week of age, positive and highly significant (P<0.01) correlations were observed between IBW and FBW in Ross strain and also between FBW, DWG and TWG in all the three strains. In addition, positive and perfect correlations existed between DWG and TWG in the three strains as well as between DFI and TFI in NAPRI-X and Marshall strains. The prediction equations for conformation traits revealed that NEL and BKL were the most significant predictors of body
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weight among the three strains. For morphological traits WTL was observed to be the most significant predictor of body weight among the three broiler strains. The PCA for conformation and morphological traits depicts highest eigen values in PC1 for both conformation and morphological traits. The percentage total variance of 84.40%, 73.54% and 88.50% for NAPRI-X, Marshall and Ross strains were adequate for conformation traits. Similarly, adequate percentage total variance of 45.57%, 90.53% and 57.56% were also obtained in morphological traits. In conclusion, it has been observed that Marshall strain was superior for growth, conformation and morphological traits at 4th and 8th weeks of age followed by NAPRI-X and Ross strains. Further study should be carried out to map the genes that make Marshall the best strain in growth, conformation and morphological traits.
TABLE OF CONTENTS
Title Page…………………………………………………………………………………….i
Declaration ………………………………………………………………………………………………………… ii
Certification ………………………………………………………………………………………………………. iii
Dedication ………………………………………………………………………………………………………… iv
Acknowledgement ………………………………………………………………………………………………. v
Abstract …………………………………………………………………………………………………………… vii
Table of contents………………………………………………………………………………………………… ix
List of figures …………………………………………………………………………………………………. xvii
List of tables ………………………………………………………………………………………………….. xviii
List of appendices ……………………………………………………………………………………………… xx
List of abbreviations……………………………………………………………………….xxi
CHAPTER ONE ………………………………………………………………………………………………. 1
1.0 INTRODUCTION………………………………………………………………………..1
1.1 Justification for the Study………………………………………………………………4
1.2 Research hypothesis……………………………………………………………………5
1.3 Objectives of the research……….…………………………………………………….5
CHAPTER TWO..…………………………………………………………………………7
2.0 LITERATURE REVIEW……………………………………………………………..7
2.1 Commercial Broiler Breeders…………………………………………………………7
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2.2 Growth Performance Traits…………………………………………………………12
.2.2.1 Feed Intake………………………………………………………………………………………………. 12
2.2.2 Body Weight …………………………………………………………………………………………….. 14
2.2.3 Feed Conversion Ratio……………………………………………………………….16
2.2.4 Mortality………………………………………………………………………………17
2.3 Live Body Measurements/Body Conformation Traits……………………………..17
2.3.1 Neck Length………………………………………………………………………….19
2.3.2 Back Length………………………………………………………………………….19
2.3.3 Shank Length ……………………………………………………………………………………………. 19
2.3.4 Thigh Length…………………………………………………………………………………………….. 21
2.3.5 Breast Width …………………………………………………………………………………………….. 21
2.3.6 Body Length …………………………………………………………………………………………….. 22
2.3.7 Wing Length …………………………………………………………………………………………….. 23
2.3.8 Correlations between Body Weight and Live Body Measurements …………………….. 24
2.3.9 Eigen Values and Percentage of Total Variance Along with the Rotated Component Matrix and Communalities of the Body Measurements…………………………………….. 27
2.4 Morphological Traits: An Over View……………………………………………………………28
2.4.1 Ocular Length and Width ……………………………………………………………………………. 28
2.4.2 Comb Height and Length ……………………………………………………………………………. 29
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2.4.3 Beak Length ……………………………………………………………………………………………… 29
2.4.4 Ear Lobe Length and Width ………………………………………………………………………… 30
2.4.5 Wattle Length and Width ……………………………………………………………………………. 32
CHAPTER THREE……………………………………………………………………….33
3.0 MATERIALS AND METHODS……………………………………………………..33
3.1 Experimental Site……………………………………………………………………..33
3.2 Source of Experimental Birds………………………………………………………..33
3.3 Experimental Birds and Their Management……………………………………….33
3.4 Experimental Design:…………………………………………………………………34
3.5 Growth Traits Measured:……………………………………………………………34
3.5.1 Feed Intake:………………………………………………………………………….34
3.5.2 Body weight:…………………………………………………………………………34
3.5.3 Feed Conversion Ratio: ………………………………………………………………………………. 35
3.5.4 Percentage Mortality: …………………………………………………………………………………. 35
3.6 Conformation Traits Measured………………………………………………………35
3.7 Morphological Traits Measured……………………………………………………..35
3.8 STATISTICAL ANALYSIS………………………………………………………….36
3.8.1 Analysis of Variance: …………………………………………………………………………………. 36
3.8.2 Correlation Analysis:………………………………………………………………………………….. 38
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3.8.3 Regression Analysis: ………………………………………………………………………………….. 38
3.8.4 Principal Component Analysis procedure: ……………………………………………………… 38
CHAPTER FOUR……………………………………………………………………………………………. 41
4.0 RESULTS……………………………………………………………………………41
4.1 Growth Performance Characterization…………………………………………..41
4.1.1 Comparative growth performance of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age …………………………………………………………………………………………….. 41
4.1.2 Correlated relationship between growth performance of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age……………………………………………………………………. 41
4.1.3 Comparative growth performance of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age …………………………………………………………………………………………….. 44
4.1.4 Correlated relationship between growth performance traits of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ………………………………………………………. 45
4.2 Measurement of Body Weight (g) and Conformation Traits (cm)…………………48
4.2.1 Comparative conformation traits of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age …………………………………………………………………………………………….. 48
4.2.2 Correlated relationship between conformation traits of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age……………………………………………………………………. 48
4.2.3 Comparative conformation traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ……………………………………………………………………………………….. 52
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4.2.4 Correlated relationship between conformation traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ……………………………………………………………. 54
4.3 Measurement of Body Weight (g) and Morphological Traits (cm)………………..56
4.3.1 Comparative morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age ……………………………………………………………………………… 56
4.3.2 Correlated relationship between morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age ……………………………………………………………. 58
4.3.3 Comparative morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ……………………………………………………………………………… 60
4.3.4 Correlated relationship between morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ……………………………………………………………. 62
4.4 Prediction Equations for 8 Weeks Body Weight using Conformation and Morphological Traits. ………………………………………………………………………………… 64
4.4.1Prediction equations for 8 weeks body weight of NAPRI-X, Marshall and Ross broiler strains using conformation traits. ………………………………………………………………….. 64
4.4.2 Prediction equations for 8 weeks body weight of NAPRI-X, Marshall and Ross broiler strains using 8 weeks morphological traits. ………………………………………….. 66
4.5 Principal Component Analysis……………………………………………………….68
4.5.1 Eigen values and share of total variance along with factor loadings and communalities of conformation traits of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age. …………………………………………………………………………………………………………. 68
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4.5.2 Eigen values and share of total variance along with factor loadings and communalities of morphological traits of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ………………………………………………………………………………………………………… ..71
CHAPTER FIVE…………………………………………………………………………..75
5.0 DISCUSSION OF RESULTS…………………………………………………………75
5.1 Growth Performance Characterization……………………………………………..75
5.1.1 Comparative growth performance of NAPRI-X, Marshall and Ross broiler strains at 4 week of age…………………………………………………………………………..75
5.1.2 Correlated relationship between growth performance of NAPRI-X, Marshall and Ross broiler strains at 4 week of age………………………………………………………76
5.1.3 Comparative growth performance of broiler strains at 8 weeks of age……………..78
5.1.4 Correlated relationship between growth performance of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age……………………………………………………..79
5.2 Measurements of Body Weight (g) and Conformation Traits (cm) at 4 weeks……81
5.2.1 Comparative conformation traits (cm) of broiler strains at 4 week of age …………….. 81
5.2.2 Correlated relationship between conformation traits of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age…………………………………………..…………82
5.2.3 Comparative conformation traits (cm) of broiler strains at 8 week of age………….83
5.2.4 Correlated relationship between conformation traits of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age……………………………………………………..84
5.3 Measurement of Body Weight (g) and Morphological Traits (cm)…………….86
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5.3.1 Comparative morphological traits (cm) of broiler strains at 4 weeks of age………..86
5.3.2 Correlated relationship between morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 4 weeks of age………………………………………………..86
5.3.3 Comparative morphological traits (cm) of broiler strains at 8 weeks of age………..88
5.3.4 Correlated relationship between morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age………………………………………………..89
5.4 Prediction Equations for 8 Weeks Body Weight of NAPRI-X, Marshall and Ross Broiler Strains using 8 Weeks Conformation and Morphological Traits………90
5.4.1 Prediction equations for 8 weeks body weight (g) of NAPRI-X, Marshall and Ross broiler strains using conformation traits (cm)……………………………………….90
5.4.2 Prediction equations for 8 weeks body weight (g) of NAPRI-X, Marshall and Ross broiler strains using morphological traits (cm)………………………………………91
5.5 Principal Component Analysis……………………………………………………….91
5.5.1 Eigen values and share of total variance along with factor loadings and communalities of conformation traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age ………………………………………………………………………………………………………. 91
5.5.2 Eigen values and share of total variance along with factor loadings and communalities of morphological traits (cm) of NAPRI-X, Marshall and Ross broiler strains at 8 weeks of age. ……………………………………………………………………………………………. 93
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CHAPTER SIX……………………………………………………………………………94
6.0 SUMMARY, CONCLUSION AND RECOMMENDATIONS…………………….94
6.1 Summary………………………………………………………………………………94
6.2 Conclusion……………………………………………………………………………..96
6.3 Recommendations………………………………………………………………………97
REFERENCES……………………………………………………………………………98
APPENDICES……………………………………………………………………………108
CHAPTER ONE
1.0 INTRODUCTION
The contribution of poultry to animal protein supply in Nigeria cannot be overemphasized. FAO (2008) estimated that, the poultry population at 137,679,000 out of this number, 115,880,864 representing 84% is backyard poultry, while 21,798,079 representing 16% are exotic poultry. Ojedapo et al. (2010) highlighted that, poultry contributed immensely as major source of animal protein for human consumption in Nigeria as they contributed about 10% of the total national livestock production. Poultry meat and egg production account for more than 30% of available animal protein (Permin and Pedersen, 2000). The International Food Policy Research Institute (IFPRI, 2000) estimated that by the year 2015, poultry will account for 40% of animal protein; however, this might be difficult to attain in Nigeria. FAO (1997) recommended 56g of animal protein intake for growing and developing individuals per day. Christopher et al. (1997) reported that Nigerians consume only 15g of animal protein per day. There has been a call for substantial increase in the intake of protein of animal origin in developing countries like Nigeria. This can be achieved through the production of animals that are prolific and have short generation interval (Abeke et al., 2003). Poultry is among the animal species with short generation interval and they are highly prolific.
Among the fastest growing livestock industries in Nigeria, poultry sub-sector was ranked first (Akanni et al., 2010). Poultry have been widely reported to possess high degree of efficiency of feed utilization with little or no socio-religious taboo in their consumption (Akanni et al., 2010). Preference for poultry production by man has also been attributed to the short growing cycle of poultry (Global plan, 1992).
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Unfortunately, poultry production is affected by several factors among which include temperature, humidity, nutrition and genetic makeup. The productivity of poultry under high temperature and humidity is low and accompanied by heavy mortality. It is of importance to develop and test poultry breeds that compete with the original breeds under these climatic conditions. However, the development of suitable strains of broiler chickens for the tropical environment is a research interest which has engaged the attention of a number of poultry geneticists and breeders for the past two decades (Ndri et al., 2007).
On the other hand, human population was believed to be increasing rapidly especially in the developing countries like Nigeria. In this regard, food production and supply are found to be lower than the rate at which population is growing especially in the developing countries. As such, breeders have done good job through continuous selection that helped to reduce the age at marketing in the last four decades; as a result, body weight of 1.5 kg in broilers which was possible at 12 weeks of age in the past can now be achieved at 6-7 weeks (Kabir et al., 2006). Genetically improved strains of poultry have been a major contribution to the success of the poultry industry, which is a major source of animal protein for human population in most countries of the world (McKay, 2009). Furthermore, improvement in health, nutrition and environmental management has also contributed to improved performance, but the majority of the changes have been attributed to genetic improvement McKay (2009). Havenstein et al. (2003 a,b) estimated that at least 85% of the improvement in performance is attributed to genetic changes. Yakubu and Salako (2009) hinted that growth is a complex and dynamic physiological process that exists from conception until maturity. Growth in any organism is a result of
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the genetic potential of the individual and genetic x environment interaction (Kor et al., 2006). Body growth in livestock may be evaluated with body components such as live weight and linear body measurements (Wolanski et al., 2006; Saatci and Tilki, 2007). Poultry breeders need some techniques to select animals for breeding purposes. Linear body measurements otherwise called conformation traits are important parameters in predicting body weight and this has been observed by commercial breeders and producers. Breeders, therefore, breed desirable sizes of chickens which also have the desirable production traits particularly body weight (Ojedapo et al., 2010).
Apart from weight, a number of conformation traits are known to be good indicators of body growth and market value of broiler (Ibe, 1989). Amao et al. (2012) reported that most of the linear body measurements reflect primarily the long bones of the animals. Such conformation traits include shank length, breast width, keel length, wing span, chicken height, body length, thigh length, and head circumference (Ojo et al., 2010a). There are other traits that are less significant nutritionally than conformation traits; these are called morphological traits otherwise called head measurements. They include comb length and height, ocular length and width, beak length, wattle length and width, ear lobes length and width. Yakubu and Salako (2009) reported that comb length, beak length, and neck length did not significantly influence body weight. The relationships between body weight and conformation traits have been found to have important implications in the production of broilers with desirable body conformation (Ibe and Nwakalor, 1987). Okon et al. (1996) highlighted that the relationships between body weight and conformation traits are direct and positive. As such knowledge of this relationship would help breeders organize their program in order to achieve optimum
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combination of body weight and conformation for maximum economic returns (Adeniji and Ayorinde, 1990). The knowledge of interrelationships among body measurements can be applied in selection and breeding (Monsi 1992). Chambers and Fortin (1984) reported that the importance of evaluating interrelationships and conformation traits in poultry lies in their usefulness as predictors of characteristics like body weight. Such applications could speed up the assessment of traits through the involvement of simple measurement tools like ruler or tape, as such simple linear measurements that can predict body weight without necessitating bird slaughter will be particularly desirable. However, body weight and body conformations are the two important parameters for measuring growth in the domestic chickens. The mechanism involved in the control of growth in chickens are too complex to be explained only under univariate analysis because all related traits are biologically correlated due to pleiotropic effect of gene and linkage of loci (Rosario et al., 2008). Principal components analysis is a mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables known as principal components which are ordered so that the first few retain most of the variation present in the original variables (Jollife, 2002). Use of principal component analysis to examine the relationship between measurement of size and shape in poultry has been reported in chicken (Ibe, 1989; Yakubu et al., 2009a), and duck (Shahin, 1996; Mc Cracken et al., 2000; Ogah et al., 2009).
1.1 JUSTIFICATION FOR THE STUDY
Poultry production is an important universal enterprise. Many poultry breeds or strains were found to survive and produce in the humid, sub-humid and semi-arid zones of the
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world; but one of the major constrains in the semi-arid zone is heat. Patra et al. (2002) reported that most of the layer and broiler breeds have originated and been developed under temperate climate, so they are more prone to tropical climatic stress as found in Nigeria. The result is decrease in feed consumption; feed efficiency accompanied with heavy mortality during summer. Broilers especially suffer more in dissipating the body heat due to their faster metabolism. Adeosun (2012) stated that, the heat stress begins at about 320C which depresses voluntary feed intake. In this context, effort is been made to develop and test breeds or strains that are tolerant to tropical environment. There are numerous breeds and strains for both meat and egg production and most of them were developed in temperate regions. In the semi-arid zone, Marshall, Ross, Hubbard and Anak have been accepted as commercial broiler chickens and so development of strains from these breeds would perhaps perform better than any of the breeds in the region.
1.2 RESEARCH HYPOTHESIS:
NULL HYPOTHESIS (Ho): There is no difference in growth, body conformation and morphological traits among NAPRI-X, Marshall and Ross broiler strains. ALTERNATIVE HYPOTHESIS (Ha): There is difference in growth, body conformation and morphological traits among NAPRI-X, Marshall and Ross broiler strains.
1.3 OBJECTIVES OF THE RESEARCH
1. To determine variations in growth performance traits of NAPRI-X, Marshall and Ross broiler strains at 4 and 8 weeks of age;
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2. To evaluate the relationships that exist between body weight, conformation and morphological traits of NAPRI-X, Marshall and Ross broiler strains at 4 and 8 weeks of age;
3. To ascertain the extent to which conformation and morphological traits could be used to predict eight weeks body weight of NAPRI-X, Marshall and Ross broiler strains.
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