ABSTRACT
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.
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
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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
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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
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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.
Moreover, the records of numerous poultry breeds genetically developed in other
continents as far back as the nineteenth century is equally interesting. According to the New
Encyclopedia Britannica (1995) the Barred Plymouth Rock, the American breed of
importance today was developed in 1865 by crossing Dominique with the Black Cochin. The
Wyandotte (an America breed) developed from five or more strains and breeds has eight
varieties. Rhode Island Red (RIR) developed in 1857 was from red Malay game fowl crossed
with reddish coloured shanghais with some brown leghorn, Cornish, Wyandotte and Brahma
blood. It is good for meat production and one of the top meat breeds for the production of egg.
It has bright red feather. New Hampshire was developed in US in 1930 from Rhode Island
Red. It is a meat and early maturing breed. The white Leghorn especially developed in the
USA, is one of the 12 varieties of the Leghorn breed which originated in Italy, a
Mediterranean breed. The white Leghorn is the leading egg producer of the world. Cornish,
an English breed, developed for crossbreeding programmes for broiler production was
developed in England before 1893. It is a poor egg producer. The white Plymouth was
registered in USA in 1888. Brahma is the only Asiatic breed of significance today developed
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in India. It has three varieties. The breeds of chicken are classified into American,
Mediterranean, European and Asiatic, depending on the regions of the world where they were
developed. The shika brown breed has been developed in NAPRI, Shika, Zaria. That means
there is no African class of chicken. This buttresses the fact that while the Europe, America
and Asia have for over a century been milking great income from their developed poultry
breeds and other developed natural resources, Africa including Nigeria has been sleeping and
groping in the dark due to many technical, socio-economic, organizational, constitutional and
institutional problems.
These considerations pose some urgency on animal scientists and the entire nation of
the need to put into motion every programme and action that will make it possible for our
nation, Nigeria, to consolidate its claim as the “giant of Africa”. Nigeria would have to fulfil
the proverb, “the proof of the pudding is in the eating”, by developing breeds of poultry for
Africa that will be called truly African breeds. It could be observed with some confidence that
the various studies carried out on gene characterization; improvement potential for meat and
egg production; biometric, allometric and anthropometric indices of the Nigerian local
chicken in cited works of Hill (1954), Nwosu (1990); have served enough background work
to justify actual breeding plans for breed development in Nigeria in the 21st century. These
studies done in the past laid a foundation for the recent findings that the light and heavy
ecotypes both genetically and phenotypically differ (Momoh 2005). Management and
nutrition affect the performance of both the heavy ecotype and the light ecotype. Heavy
ecotype performs better than light ecotype and the battery cage performance has an edge over
that in the deep litter (Tule 2005). The local chicken by nature is rugged and would require a
feed of intermediate standard rather than depending on/or adopting the standard form from
improved breeds put forward by NRC (Tule 2005). The relevance of the ongoing Ph. D
research works of Ogbu, Cosmos and Ewa, Vivian, who are supervised by Professor Emeritus
Dr. C.C. Nwosu on selection for growth and egg laying parameters on the heavy ecotype and
light ecotype of the Nigerian local chicken is indisputable in the characterization of the local
chicken of Nigeria. The researches and findings so far carried out on the Nigerian local
chicken put the goal of breed development in Nigeria on course. The findings will provide the
basis for the development of a poultry breed in Nigeria.
Great care, therefore, must be taken to equally develop the best plan that can
maximally utilize the information found on the Nigerian Heavy and Light ecotype chicken for
the purpose of developing a new breed at a minimal cost and shortest possible time.
According to FAO (2004), strategies to develop poultry breeds suitable for family poultry in
tropical countries must differ from those used in intensive production and should focus on
improving indigenous breed, while also making use of pure, exotic and crossbred chickens
where appropriate. FAO (2004) and Nwosu (1989) recommended the following rules in
improving the Nigerian breed (i) Germplasm in the traditional condition should not be
modified until management and housing have been improved, even then selection should be
restricted to local breed, FAO (2004). (ii) When technical conditions are optimum and a ready
market exist for the products, then the improved breeds, crosses and hybrid that have been
selected for high performance can be introduced into the peri urban system even at small scale
level (FAO, 2004). Hence according to Nwosu (1989) (an unpublished research work) care
3
must be taken to avoid the mistakes of the scientists and government of Nigeria in the past
before publication of Agricultural policy for Nigeria, which almost destroyed the hardy and
less productive local breeds by indiscriminate crossing of local breeds of livestock and
poultry. Replacement of local breeds with exotic breeds as a development strategy is a wrong
strategy. Any breeding programme that excludes local genetic resource may be unrealistic.
Appropriate rules and breeding programmes for the development of Nigeria breeds of poultry
may indeed include pure breeding and selection programmes of the heavy and light ecotypes
of the Local chickens in order to produce a Nigerian broiler, layer or dual purpose.
Pure breeding is a type of inbreeding where by mating is carried out between relatives
(Pirchner 1969) or inbreeding involves mating between a male and female who are more
related than the average of the population. Pure breeding of heavy ecotype of Nigerian local
chicken means a mating between a heavy ecotype male and heavy ecotype female. Burdette
(1963) described this kind of mating as incross, which is one of the four kinds of mating.
Other matings include crosses, backcrosses and intercrosses. Allelemorph A and its
alternative allele may be used to describe dominant and recessive alleles on a particular locus.
AA x AA and aa x aa represent matings of like homozygotes or incrosses. Purebreeding of the
heavy ecotype can be designated as AA x AA whereas that of the light ecotypes as aa x aa.
The breeding system was also categorized into seven systems by Burdette (1963). The
purebred experimental work will make use of the first breeding system (random-mating
system). According to Pirchner (1969) the principal tools for improvement are selection,
inbreeding and crossing. Which of these combinations to use depends on the species, breeding
goal, trait, breeding structure and other considerations. If the additive – genetic variance is
reasonably important, selection is the proper method. If genotypic variation is non-additive,
selection alone will be inefficient. If dominance, particularly over dominance effect, is
operational, inbreeding followed by crossing or selection will be successful. At any rate
crossbreeding is important. If epistatic effect is the mode of gene action, inbreeding and
selection are efficient. Pedigree breeders particularly elite group must practice pure breeding
or even inbreeding and selection (Pirchner 1969).
1.1 Objectives of The Pure Breeding Experiment
(A) MAIN OBJECTIVE: To achieve a genetic improvement of the heavy ecotype of the
local chickens of Nigeria through like to like matings.
(B) SPECIFIC OBJECTIVES:
i. To investigate data on body weight, body weight gain, egg performance of purebreds
of the heavy ecotype of the Nigerian local chicken and make comparisons between
the purebred generation and the random-bred population of heavy ecotype in the
farm.
ii. To determine body length, shank length, feather, beak and egg colour characteristics
of the random-bred population and purebreds of the heavy ecotype of the local
chicken and make comparisons between them.
iii. To investigate the hatchability percentages so that the best condition for hatchability
using the backward integration method can be determined.
4
iv. To estimate the heritability of body weight, body weight gain, body length, shank
length, feather colour, beak and egg colour through the sire components analysis (Sib
analysis or Estimation of heritability from half Sibs).
v. To investigate other genetic parameters such as correlation and regression
coefficients.
vi. To estimate feed indices such as feed intake, feed efficiency, (kg/g of gain) and feed
cost per purebred for the various ages; 0-8 weeks, 8-20 weeks and short term egg
production.
1.2 JUSTIFICATION
Intensive research work on the local chicken is justified by the following reasons:
a. The renowned scientific work of Maughan (1978) showed that good health starts with
good nutrition. Scientific research has linked the consumption of saturated fatty acids,
found predominantly in animal fats, with increased levels of cholesterol and a higher
risk of heart attacks, while the unsaturated variety from vegetable oils and chickens
do not have that effect. The findings of Obanu et al (1985) that the local chicken
appears more compact and yield more meat per unit of live weight than the exotic;
and contains smaller molecular weight fats with low Saponfication value indicate the
need to develop a local (Nigerian) breed of poultry with lean meat is possible and
very urgent.
b. The problems of low animal protein intake in Nigeria will
tremendously be addressed when novel indigenous breeds are developed through pure
breeding to cause chicken meat and egg prize to drop drastically.
c. Hitherto, work on the local chicken has been too broad. Researchers refer to the local
chicken as if all local brids are of the same size or possessing the same characteristic.
Through the works of Momoh (2005) and Tule (2005) it has become clear that there
are light and heavy ecotypes of the local chicken.
d. Since FAO (2004) and Nwosu, (1989) unprinted research work recommended that the
germplasma of the local chicken should not be unscrupulously modified but must be
jealously preserved; this suggests that the gene pool of the heavy and light ecotype of
the Nigerian local chicken should be preserved and utilized through pure breeding.
e. The two tools for genetic improvement are mating method or breeding system and
selection (Burdette, 1963). It will be important to aggregate the genetic potentials of
the heavy ecotype through pure breeding research especially considering the recent
reports of Tule (2005) that the heavy ecotype perform better than the light ecotype.
Pure breeding of the heavy ecotype of the Nigerian local chicken presupposes the
mating of heavy ecotype males with the heavy ecotype females on a continuous basis
for purification. This is the same as mating of relatives, since all heavy ecotypes of
the Nigerian local chicken have the same ancestors.
5
f. Development of the indigenous species of poultry into pure breeds of known genetic
merit will add value to our animal genetic resources.
g. Such Nigerian breeds of poultry when utilized commercially will largely increase the
Gross Domestic product (GDP) of the Nation and greatly enhance our economy.
h. Nigeria as a nation, desperately would needs to reduce the cost of foreign exchange
expenditure incurred through the importation of fertile eggs, day old chicks and
parent stock to Nigeria. An indigenous broiler, layer or dual purpose breed developed
through pure breeding and selection methodology would not only terminate this
problem but also at the same time become a major source of generating foreign
exchange.
i. According to Pekinbantams (2005), the United Kingdom, Australia, South Africa and
America have their individual breed and colour standards. Nigeria also has need for
her own breed and colour standards as it will lead her to the path of self- sufficiency
instead of importation of finished products from abroad.
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