TABLE OF CONTENTS
Title page – – – – – – – – – i
Certification – – – – – – – – – ii
Dedication – – – – – – – – – iii
Acknowledgments – – – – – – – – iv
Table of contents – – – – – – – – v
List of table – – – – – – – – – viii
Abstract – – – – – – – – – x
CHAPTER ONE: INTRODUCTION – – – – – – 1
1.1 Justification – – – – – – – – 3
1.2 Objectives of the pure breeding experiment – – – – 4
CHAPTER TWO
2.0 Literature review – – – – – – – 6
2.1 The genetic resources of the indigenous African chicken – – – 6
2.2 Body weight – – – – – – – – 8
2.3 Egg production traits – – – – – – – 11
2.4 Egg weight – – – – – — – – 11
2.5 Body weight at first egg (BWFE) and weight of first egg (WFE) – – 12
2.6 Broodiness – – – – – – – – 12
2.7 Age at first egg (AFE) – – – – – – – 12
2.8 Allometric growth traits – – – – – – 12
2.9 Potentials of Nigerian local chickens for genetic improvement – – 13
2.10 Purebreeding of the Nigerian local chickens – – – – 15
2.11 Purebreeding and its consequencies in small populations – – – 16
2.12 Colour standard of exotic breeds – – – – – – 20
2.13 UK breed standards – – – – – – – 20
2.14 Chicken genomics (chicken gene mapping and sequencing) – – 22
2.15 Genetic parameters in chicken – – – – – – 22
2.15.1 Heritability – – – – – – – – 22
CHAPTER THREE
3.0 Material and methods – – – – – – – 27
3.1 The study site – – – – – – – – 27
3.2 Foundation stock – – – – – – – 27
3.3 Multiplication of birds using the backward integration ethod of momoh (2005) 27
3.3.1 Natural incubation-forward integration – – – – – 28
3.4 Management of experimental birds – – – – – 28
3.5 Parameters to be measured – – – – – – 29
3.5.1 Growth traits – – – – – – – – 30
3.5.2 Feed indices – – – – – – – – 30
3.5.3 Biometrical traits – – – – – – – 30
3.5.4 Colour traits – – – – – – – – 30
3.5.5 Fertility traits – – – – – – – – 31
3.5.6 Mortality – – – – – – – – 31
3.5.7 Allometric traits – – – – – – – 31
3.5.8 Quantitative measurement – – – – – – 31
3.6 Statistical methods – – – – – – – 32
CHAPTER FOUR
4.0 Results – – – – – – – – – 34
4.1 Growth traits – – – – – – – – 34
4.1.1 Body weight – – – – – – – – 34
4.1.2 Average body weight gain – – – – – – 39
4.1.3 Feed indices- – – – – – – – – 39
4.1.3.1 Average feed consumption, AFC (G) – – – – – 39
4.1.3.2 Feed conversion ratio (FCR) – – – – – – 39
4.1.4 Biometrical traits – – – – – – – 39
4.1.4.1 Body length – – – – – – – – 39
4.1.4.2 Shank length – – – – – – – – 40
4.1.5 Colour traits – – – – – – – – 40
4.1.5.1 Down feather colour – – – – – – – 40
4.1.5.2 Shank colour – – – – – – – – 40
4.1.5.3 Beak colour – – – – – – – – 41
4.1.5.4 Egg colour – – – – – – – – 41
4.1.6 Fertility traits – – – – – – – – 41
4.1.6.1 Infertility-mortality – – – – – – – 41
4.2 Genetic evaluation of growth rates – – – – – 43
4.3 Correlations – – – – – – – – 46
4.4.0 Allometrical traits – – – – – – – 51
CHAPTER FIVE
5.0 Discussion – – – – – – – – 55
5.1 Growth traits – – – – – – – – 55
5.1.1 Body weight – – – – – – – – 55
5.1.2 Body weight gain and mean consumption – – – – 55
5.1.3 Biometrical traits – – – – – – – 56
5.1.3.1 Body length — – – – – – – – 56
5.1.3.2 Shank length – – – – – – – – 56
5.1.4.0 Colour traits – – – – – – – – 56
5.1.4.1 Down feather colour – – – – – – – 56
5.1.4.2 Shank colour – – – – – – – – 56
5.1.4.3 Beak colour – – – – – – – – 57
5.1.4.4 Egg colour – – – – – – – – 57
5.2.0 Genetic evaluation of various growth traits – – – – 57
5.2.1 Heritability estimates – – – – – – – 57
5.2.2 Genetic (rG) and phenotypic (rP) correlation between various growth traits 59
5.3 Allometric traits – – – – – – – – 60
CHAPTER SIX
6.0 Conclusion and recommendations – – – – – 61
6.1. Conclusion – – – – – – – – 61
6.2 Recommendation – – – – – – – 62
References – – – – – – – – – 65
LIST OF TABLES
Table 1: Estimates of heritability of some traits of commercial breeds in different countries– — — — — — — — — 24
Table 2: The phenotypic, genetic and environmental correlations of some traits in chickens — — — — — — — — — 26
Table 3: Percentage (%) composition of the commercial and formulated diets used for the experiments.– — — — — — — — 29
Table 4: Sib analysis of variance and descriptive statistics for body weight (grammes)
of five genetic groups of purebred of the Nigerian heavy ecotype chicken 34
Table 5: The Duncans multiple range tests of the means (± sd) of various traits (0 to 20 weeks)
of progeny in five genetic groups of local chicken raised intensively – 38
Table 6: Heritability estimates of various traits – – – – – 43
Table 7: The components (sire and dam) of genetic (rG), phenotypic (rP) and Environmental (rE)
correlations of various traits of heavy ecotypes of the Nigerian local chickens 46
Table 8: The mean values of the various organs at different age periods — — 51
Table 9: Percentage of body weight contributed by various organs – — 52
Table 10: Growth coefficient of the traits at different age periods– — — 54
ABSTRACT
Fifty five (55) experimental birds were randomly replicated into 5 deep litter pens in the ratio of 1 cock: 10 hens. Like to like random mating was ensured to raise 200 chicks in the F1 generation.
Chicks were subjected to measurements like body weight, body length, shank length, shank colour, beak colour, feather colour, feed conversion ratio, mean feed consumption, egg colour, egg fertility, egg hatchability, dead embryo and mortality at hatch and subsequently at 4 weekly intervals.
Data obtained from these traits at ages of 0 (day old) – week, 4-weeks, 8-weeks,12-weeks 16-weeks and 20 weeks were subjected to analysis of variance (ANOVA) in a nested or hierarchial design and in a paternal half sib analysis using SAS (2004) statistical procedure.
Body weight was significantly different among the progeny and ranged from 30.33g at day old to 1334.67g at 20 weeks of age. Sire had no significant effect in average body weight gain (ABWG), expect at 8-12weeks of age. ABWG ranged from 85.05g at 4 weeks to 441.20g at 20 weeks of age.
There was significant (p<0.001) difference in feed conversion ratio (FCR) at 12 weeks of age. Sire had highly significant (p<0.001) effect on average feed consumption (AFC) from 4-20 weeks of age.
Sire had significant (p<0.05) effect on body length (BL) at 12 and 20 weeks of age. Sire had significant (p<0.05) effect on shank length at 0 week of age.
Sire had highly significant (p<0.001) effect on shank colour at day old and it ranged from cream colour to cream black colour.
Sire had highly significant (p<0.001) effect on the beak colour at 0 week, which ranged from cream to cream hazenut.
There were highly significant differences (p<0.001) in the number of white, light brown and brown eggs laid by the hens mated to the sires. With respect to the down feather colour of the progeny, sire did not make any difference. Sire used made no differences (p>0.05) in the number of infertile eggs laid throughout the experiment. Sire significantly (p<0.001) influenced the hatchability of eggs laid, the number of embryos that died in the shell and the number of chicks that died after hatching.
The heritability estimates of body weight (BW) ranged from 0.05 at 4 weeks to 0.54 at 12 weeks of age. The body length (BL) heritability estimates ranged from 0.06 at 4 weeks to 0.80 at 0 weeks. Heritability estimates of shank length (SL) ranged from -0.12 at 16 weeks to 0.80 at 0 week of age. Heritability estimates for shank colour, beak colour and feather colour were 1.38, 0.80 and 0.17 respectively. The average feed consumption heritability estimates ranged from 0.16 at 4 weeks to 2.00 at 8 weeks. Heritability estimates for feed conversion ratio ranged from -0.15 at 4 weeks to 1.15 at 12 weeks. Heritability estimates ABWG ranged from -0.10 at 16 weeks to 1.16 at 12 weeks of age.
The phenotypic correlation (rP) was in the range of -0.0178 between BW and BC at hatch to 0.6496 between BL and SL at 20 weeks of age.
The genetic correlation, rG (sire) ranged from -0.22 between BW at 8 weeks and BW at 20 weeks of age to 1.7298 between BW and SL at hatch.
The data on all the traits studied indicate that the heavy ecotype could form a foundation stock for layer, meat and dual purpose breed development in Nigeria.
CHAPTER ONE
INTRODUCTION
Evidence abounds that Nigeria as a Nation is endowed with surplus natural resources that will make her self-sufficient in animal protein production and even become main exporters of all kinds of food items. According to Nigerianet (2003), Nigeria, being the largest geographical unit in West Africa, has a land area of 923,768 square kilometers. According to Central Bank of Nigeria, CBN (2002), Nigeria population was reported to be 129.9 million in 2004 based on the projected annual growth rate of 2.8% of the revised 1991 census. At this given growth rate Nigeria population is estimated to be 141.1 million in 2007. Nwosu (1989) reported that of the one hundred and thirty three million (133,000,000) chickens in Nigeria, one hundred and twenty-three million (123,000,000) are local chickens. RIM (1992), reported that the native chickens constituted 80% of the one hundred and twenty million (120,000,000) chickens in Nigeria. This showed that ninety-six million (96,000,000) were native chickens.
The fact that some developed countries with far less natural resources can still boast of self sufficiency and their ability to export poultry products call for sober reflection among Nigerians. Frommer (2006), the Israeli Ambassador to Nigeria, reported that Nigeria’s geographical territory is 30 times bigger than that of Israel and it’s population is 20 times larger than that of Israel. Annual rainfall in Israel ranges from 28 inches (70cm) in the north to less than 2 inches (5cm) in the south. Despite the obvious disparity in natural resources between Nigeria and the State of Israel, it is believed that the Israel model of agricultural and research development with some necessary modifications could be applied in Nigeria. Israeli livestock output for instance, in 2004 was worth US $1.4 billion (39%) and crops US $2.5 billion (61%). Israel produced almost 70% in monetary terms of its food requirements. The recent purchase of twenty five thousand (25,000) day old broiler chicks from Israel by the Animal Science Department of the University of Nigeria, Nsukka, in her HUJII broiler project, to a large extent, substantiates the Israeli Ambassador’s claims.