TABLE OF
CONTENTS
Title Page .. .. .. .. .. .. .. .. .. i
Certification .. .. .. .. .. .. .. .. ii
Dedication .. .. .. .. .. .. .. .. .. iii
Acknowledgement .. .. .. .. .. .. .. iv
Table of contents .. .. .. .. .. .. .. v
List of Tables .. .. .. .. .. .. .. .. viii
List of figures .. .. .. .. .. .. .. .. ix
Abstract .. .. .. .. .. .. .. .. .. x
CHAPTER ONE
Introduction
- Background .. .. .. .. .. .. .. 1
- Statement of problem .. .. .. .. .. 3
- Objectives of study .. .. .. .. .. 3
- Justification of study .. .. .. .. .. 4
CHAPTER TWO
Literature Review
2.1 Classification
of chickens .. .. .. .. .. 5
2.2 Exotic
breed of laying birds .. .. .. .. .. 5
2.3 The
reproductive system of the laying hen .. .. 6
2.3.1 The
Ovary .. .. .. .. .. .. .. .. 7
2.3.2 The
Oviduct .. .. .. .. .. .. .. 8
2.3.3 Ovulation .. .. .. .. .. .. .. .. 9
2.3.4 Egg
formation .. .. .. .. .. .. .. 12
2.4 Oviposition .. .. .. .. .. .. .. 12
2.4.1 Sequential
laying .. .. .. .. .. .. 13
2.4.2 Sequence/Clutch
length .. .. .. .. .. .. 15
2.4.3 Pause
days .. .. .. .. .. .. .. 15
2.4.4 Ovpiosition
time .. .. .. .. .. .. .. 16
2.4.5 Time
interval between successive eggs and lag .. .. 16
2.4.6 Total
egg production .. .. .. .. .. .. 17
2.4.7 Rate/Intensity
of lay .. .. .. .. .. .. 17
2.5 Egg
quality .. .. .. .. .. .. .. 18
2.5.1 Egg
weight .. .. .. .. .. .. .. 19
2.6 Physical
characteristics of hens .. .. .. .. 19
2.7 Climatic
condition .. .. .. .. .. .. 21
CHAPTER THREE
Materials and Methods
- Location and duration of study .. .. .. .. .. 23
- Experimental birds .. .. .. .. .. .. 25
- Management of hens .. .. .. .. .. .. 25
- Parameters measured .. .. .. .. .. 25
- Oviposition time .. .. .. .. .. .. 25
- Total egg production .. .. .. .. 25
- Clucth/sequence length .. .. .. .. .. 26
- Pause days .. .. .. .. .. .. .. 26
- Egg weight .. .. .. .. .. .. .. 26
- Egg quality .. .. .. .. .. .. .. 26
- Average daily feed intake .. .. .. 27
- Percentage egg production .. .. .. 27
- Physical characteristics .. .. .. .. .. .. 27
- Temperature .. .. .. .. .. .. .. .. 28
- Experimental design .. .. .. .. .. .. ..
- Statistical analysis .. .. .. .. .. .. .. 28
CHAPTER FOUR
Results and discussion
4.1 Results
4.1.1 Egg
laying characteristics of Shaver brown hens .. 29
4.1.1.1 Oviposition
time .. .. .. .. .. .. .. 29
4.1.1.2 Total
egg production .. .. .. .. .. .. 31
4.1.1.3 Clutch
length .. .. .. .. .. .. .. 31
4.1.1.4 Pause
days .. .. .. .. .. .. .. .. 37
4.1.1.5 Egg
weight .. .. .. .. .. .. .. .. 37
4.1.1.6 Intensity/
Rate of lay .. .. .. .. .. .. 37
4.1.1.7 Hen
housed egg production (HHEP) .. .. .. .. 39
4.1.1.8 Hen
day egg production (HDEP) .. .. .. .. 39
4.1.2 Egg laying characteristics of Nera
black hens .. .. 41
4.1.2.1 Oviposition
time .. .. .. .. .. .. .. 41
4.1.2.2 Total
egg production .. .. .. .. .. .. 43
4.1.2.3 Clutch
length .. .. .. .. .. .. .. 43
4.1.2.4 Pause
days .. .. .. .. .. .. .. .. 50
4.1.2.5 Egg
weight .. .. .. .. .. .. .. 50
4.1.2.6 Intensity/
Rate of lay .. .. .. .. .. 50
4.1.2.7 Hen
housed egg production (HHEP) .. .. .. 51
4.1.2.8 Hen
day egg production (HDEP) .. .. .. 51
4.1.3 Effect of temperature on performance
of Shaver brown
and Nera black hens .. .. .. .. .. .. 55
4.1.4 Interaction of strain and temperature
on Performance .. 57
4.1.5 Physical characteristics of hens .. .. .. .. 57
4.1.6 Comparison between strains for
performance and egg
quality traits .. .. .. .. .. .. .. .. 58
4.2.1 Climatic
data for Nsukka .. .. .. .. ..
.. 60
4.2.2.1 Egg
laying characteristics of Shaver brown
and Nera black hens .. .. .. .. .. 60
- Oviposition time .. .. .. .. .. .. .. 60
- Total egg production and other egg production Indices .. 61
- Clutch length .. .. .. .. .. .. .. 61
- Pause days .. .. .. .. .. .. .. .. 62
- Egg weight .. .. .. .. .. .. .. .. 62
- Effect of temperature on performance of Shaver brown and Nera black hens .. .. .. .. 63
- Interaction of strain and temperature on performance .. 65
- Physical characteristics .. .. .. .. .. .. 67
- Comparison between strains for performance and egg quality traits.. .. .. .. .. .. .. .. 69
CHAPTER FIVE
Summary and conclusion .. .. .. .. .. .. 71
References .. .. .. .. .. .. .. .. .. 72
Appendices .. .. .. .. .. .. .. .. 81
LIST
OF TABLES
Table 1: Times of egg laying in hens .. .. .. .. 14
Table 2: Mean weekly environmental temperatures and relative humidity during the period of the study .. .. .. .. .. .. 24
Table 3: Frequency
distribution of egg production of Shaver brown hens .. 30
Table 4: Frequency
distribution of mean clutch length of Shaver brown hens 32
Table 5: Effect of egg
position and clutch size on egg weight of Shaver brown hens 33
Table 6: Frequency
distribution of pause days of Shaver brown hens 34
Table 7: Effect of
oviposition interval on egg weight of Shaver brown hens.. 36
Table 8: Frequency
distribution of egg laying of Shaver brown and Nera
black hens during the day .. .. .. .. .. .. 38
Table 9: Classification
of experimental hens .. .. .. .. .. 40
Table 10: Frequency
distribution of egg production of Nera black hens .. 42
Table 11: Frequency
distribution of mean clutch length of Nera black hens .. 44
Table 12: Effect of egg position and clutch size on egg
weight of Nera black hens 45
Table 13: Frequency distribution of pause days of Nera
black hens .. .. 46
Table 14: Effect of oviposition interval on egg weight
of Nera black hens .. 49
Table 15: Comparison between strains for performance
and egg quality traits 52
Table 16: Effect of temperature on performance of
Shaver brown hens .. 63
Table 17: Effect of temperature on performance of Nera
black hens 54
Table 18: Effect of interaction of strain
and temperature on performance 56
LIST
OF FIGURES
Figure 1: Frequency distribution of egg laying of Shaver brown hens
at different oviposition intervals during the
day .. .. 35
Figure
2: Frequency distribution of egg
laying of Nera black hens
at different oviposition intervals during the
day .. .. 47
Figure 3: Average weekly temperatures (Indoor and Outdoor) and relative
humidity
of the study area .. .. ..
.. .. 48
ABSTRACT
A total of one
hundred and fifty Shaver brown and Nera black hens in their 14th
week of lay were used in a study conducted to determine the laying and physical
characteristics of Shaver brown and Nera black hens under humid tropical
environment. Hens were housed individually in separate cages. The hens were
supplied water ad libitum and fed
layers mash containing 16.5% crude protein and 2650 kcal/kg of metabolizable
energy for 10 weeks. The hens were also divided into three classes based on
their laying performance as follows: good layers, intermediate layers and poor
layers and their physical conditions appraised. Temperature readings were taken
3-hourly at time intervals of 0900h, 1200h, 1500h, and 1800h using a standard
air thermometer and the mean daily temperatures noted. The climatic data taken
during the period of the experiment showed that the study area had the natural
day-length of 13 to 14 hours; mean maximum weekly indoor and outdoor
temperatures of 27.90C to 29.20C and 26.80C to
30.50C, respectively; mean minimum weekly indoor and outdoor temperatures
of 20.50C to 22.30C and
20.00C to 23.600C, respectively; relative humidity of
73.1% to 76.6% and mean total monthly rainfall of 781.33mm. Results showed that the peak of lay was between
0700h and 0800h and declined gradually throughout late afternoon hours until no
egg was laid between 1700h and 1800h. For Shaver brown hens, about 86.24% and
13.76% of the eggs were laid in the morning and afternoon hours respectively,
while 88.75% and 11.25% of the eggs were laid in the morning and afternoon hours
respectively, for Nera black hens. Mean egg weight of 70.05g±1.07 and
70.10g±0.92 for eggs laid between 0600h and 0700h for Shaver brown and Nera
black hens, respectively were the heaviest (P<0.05) of all the mean egg
weights observed in all oviposition intervals. For Shaver brown hens,
first eggs laid in a clutch were
significantly greater (P<0.05) than subsequent eggs laid in a clutch, while
the first eggs in a clutch for Nera black were greater than other eggs in the
clutch, although the differences were not significant (P>0.05). Hens with
the longest clutches and shortest number of pause days produced the greatest
number of eggs. The total number of pause days observed were 1410 and 1329 for
Shaver brown and Nera black hens, respectively. Observations made on physical
characteristics of the hens revealed that good layers had smooth combs and
wattles, moist and enlarged vents with flexible pubic bone, soft abdomen and
worn out feathers. Intermediate layers had similar features with good layers
except that the eye rings, beaks and shanks were slightly bleached. Poor layers
had dry combs and wattles, tight and hard abdomen and closed pubic bones. The
Effect of ambient temperature on performance parameters showed that for Shaver
brown hens, hen day egg production, average daily feed intake, egg shell
weight, egg shape index, albumin height, yolk height, yolk height and Haugh
units were significantly reduced (P<0.05) with increasing temperatures. All
performance parameters measured for Nera black hens were significantly reduced
(P<0.05) with increasing temperatures. Likewise, there was significant
interaction (P<0.05) of strain and temperature on average daily feed intake
and yolk height. The results of the present study indicate that although heat
stress had effect on performance, Shaver brown and Nera black hens are adapted
to humid tropical environment and can lay 86.24% and 88.75% eggs, respectively
in the morning hours, with overall production rate of 66.43% and 68.36%
respectively, for Shaver brown and Nera
black hens.
CHAPTER ONE
