Effect of different energy to protein ratiosindiet and varying levels of cassava and copra meals at 1 to 21 days of age on the subsequent meat production performance of F1 mia x luong phuong chicken

EFFECT OF DIFFERENT ENERGY TO PROTEIN RATIOS IN DIETS AND
VARYING LEVELS OF CASSAVA AND COPRA MEALS AT 1 TO 21
DAYS OF AGE ON THE SUBSEQUENT MEAT PRODUCTION
PERFORMANCE OF F1 MIA × LUONG PHUONG CHICKEN

A Dissertation
Presented to the Faculty of the
Graduate Studies and Applied Research
College of Agriculture
LAGUNA STATE POLYTECHNIC UNIVERSITY
Siniloan, Laguna
Philippines

In Partial Fulfilment
of the Requirements for the Degree
Doctor of Philosophy in Agriculture
Major in Animal Science

NGUYEN THI BICH DAO
December, 2017

i


Republic of the Philippines
LAGUNA STATE POLYTECHNIC UNIVERSITY
Siniloan, Laguna
Integrity, Professionalism
and Innovation

COLLEGE OF AGRICULTURE

GRADUATE STUDIES AND APPLIED RESEARCH

This dissertation entitled “EFFECT OF DIFFERENT ME TO PROTEIN
RATIOS IN DIETS AND VARYING LEVELS OF CASSAVA AND COPRA MEALS
AT 1 TO 21 DAY OF AGE ON THE SUBSEQUENT MEAT PRODUCTION
PERFORMANCE OF F1 (MIA × LUONG PHUONG) CHICKEN” prepared by
MRS. NGUYEN THI BICH DAO in partial fulfillment of the requirements for the
degree of Doctor of Philosophy in Agriculture, major in Animal Science has been
examined and recommended for acceptance and approval.
NESTOR M. DE VERA, Ph.D.
Adviser
TRAN THANH VAN, Ph.D.
Co-Adviser
PANEL OF EXAMINERS
Approved by the committee on Oral Examination with the grade of
NESTOR M. DE VERA, Ph.D.
Chairman
LOLITA L. BEATO, Ph.D.
Member
ROBERT C. AGATEP, Ph.D.
Member

LOLITA D. VIYAR, Ph.D.
Member
VINCENT BRYAN C. CASIMERO, DVM.
Member

Accepted and approved in partial fulfillment of the requirements for the
degree of Doctor of Philosophy in Agriculture, major in Animal Science.

LOLITA L. BEATO, Ph.D.
Dean, Graduate Studies
& Applied Research
MA. GRACIELA C. PRADILLADA, R. G. C.
University Registrar III
Research Contribution No.
Passed the Comprehensive Examination

ii


ACKNOWLEDGMENT
The author wishes to express her gratitude to all the people who have
helped her to accomplish this dissertation and also made her college life very
colorful. First of all, her sincerest thanks is extended to her adviser President.
Dr. Nestor M. de Vera, for his intellectual insights, valuable advice, constant
encouragement, and hospitality. Grateful acknowledgment is extended to Dr.
Tran Thanh Van, Co-adviser for her constructive suggestions. Heartfelt thanks
to the members of her advisory committee: Dr. Lolita L. Beato, Dr. Robert C.
Agatep and Dr. Lolita D. Vyar for their valuable comments, sincere concern, and
understanding. Likewise, thanks go to the administrative staff of Agriculture
College, and the Faculty of LSPU, Siniloan Campus for their great support.
Special thanks to Dr. Nguyen Thi Thuy My, Prof. Olivia P. Magpily for their
constructive suggestions and warm encouragement. To all the faculty members
of Animal Science and Veterinary Medicine, TUAF for the permission to go on
study leave. Deepest gratitude to her loving parents and parents in law, to her
sisters, brothers in law, her sisters for all their sacrifices, encouragements and
prayers. Near is extended forever grateful to her loving husband Dr. Nguyen Duc
Truong and her sons, Nguyen Duc Kiet and Nguyen Minh Khoi, for their love and
spiritual support.

Lastly, sincere thanks to all her friends for their help and support during
my stay in the Philippines and in the conduct of experiments.

iii


DEDICATION
To all my family members

iv


ABSTRACT

Two studies were conducted 1) to evaluate the effect of ME to protein
rations in diet from 1 to 21 day of age on production performance and carcass
characteristics of F1 (Mia × Luong Phuong) chicken (Study 1); 2) to determine
the Effect of different cassava and copra meal levels in diet from 1 to 21 day of
age on production performance, caloric efficiency and carcass characteristics
of F1 (male Mia × female Luong Phuong) chicken (Study 2). These studies
attempted to find answers to the specific questions presented in Chapter 1. In
Study 1, 200 day-old, F1 (Mia × Luong Phuong) chicks were randomly allotted
to 1 of 5 treatments following a randomized complete block design (RCBD).
There were 4 replicate cages per treatment with 10 birds in each cage. The
treatments were used in this study were four ratios of ME to CP in diet of 150,
142.5, 135.7, 129.5 and 123.9. In Study 2, 640 day-old, F1 (Mia × Luong
Phuong) chicks were randomly allotted to 1 of 16 treatments following a
randomized complete block design (RCBD). The factors that were used in this
study were 4 levels of cassava meal (0, 5, 10 and 10%) and 4 levels of copra
meal (0, 5, 10 and 15%) in booster diets. There were 4 replicate cages per

treatment with 10 birds in each cage.
Results of Study 1 showed that from 1 to 21 day of age of F1 Mia × Luong
Phuong chicks fed diet containing ME to CP ratio of 142.5 had the best (P<0.05)
growth performance, CP utilization, caloric efficiency and economic return.
Ratios of ME to CP in diets of booster diet did not affect on ADFI and livability.
The ratios of ME to CP during booster phase did not affect growth performance

v


of grower, finisher phases and carcass yield at day 84 of age. Results of Study
2 showed that replace yellow corn with as much as 10% cassava meal in
booster diet of F1 Mia × Luong Phuong without negatively affecting growth
performance, FCR, livability, CP utilization, caloric efficiency and income over
feed cost. Copra meal in booster diet of F1 Mia × Luong Phuong negative affect
on growth performance, FCR, CP utilization, caloric efficiency and income over
feed cost. Copra meal in booster diet negative affect on feed efficiency of
chicken overall period (1 to 84 days of age). Cassava and copra meals levels in
booster diets did not affect carcass yield at day 84 of age.
Booster diet of F1 Mia × Luong Phuong during 1 to 21 days of age
containing ME to CP ratio of 142.5 to achieve maximum growth performance
and income over feed cost. Yellow corn can replace with 10% cassava meal in
booster diet from 1 to 21 days of age of F1 Mia × Luong Phuong. However, the
price of cassava meal, soybean meal, synthetic amino acids, and supplemental
oil should be considered. Copra meal should not be supplemented in booster
diet of F1 Mia × Luong Phuong.

vi

TABLE OF CONTENT

Contents
ACKNOWLEDGMENT ........................................................................... iii
DEDICATION............................................................................................iv
ABSTRACT ................................................................................................ v
LIST OF TABLES.................................................................................... ix
LIST OF FIGURES ...................................................................................x
Chapter 1 ....................................................................................................1
THE PROBLEM AND ITS BACKGROUND ..........................................1
Introduction ............................................................................................1
Background of the Study .....................................................................3
Theoretical Framework of the Study ..................................................6
Scope and Limitation of the Study ...................................................10
Definition of Terms..............................................................................11
REVIEW OF RELATED LITERATURE AND STUDIES ...................14
Related Literature ...............................................................................14
Related Studies ...................................................................................32
METHODOLOGY ....................................................................................35
Research Design.................................................................................35
Subject of the study ............................................................................37
Determination of the Sample ............................................................37
Research Procedures ........................................................................38
Data processing and Statistical Analysis ........................................47
PRESENTATION, ANALYSIS AND INTERPRETATION OF DATA
...................................................................................................................49
This chapter presents, the comparative analyzes, and
interpretation of the data gathered in determining the
effectiveness of energy to protein ratios on production
performance, protein and caloric efficiency, carcass

characteristics, and economic indices of crossbred native
chicken Mia × Luong Phuong. And also in determining the effects
vii


of cassava meal and copra meal levels on production
performance, protein and caloric efficiency, carcass
characteristics, and economic indices of crossbred native
chicken Mia × Luong Phuong. ..........................................................49
Study 1. Effects of ME to protein ratios in diet at 1 to 21 days of
age on production performance and carcass characteristics of F1
Mia × Luong Phuong chicken ...........................................................49
Growth Performance ......................................................................49
Efficiency of Protein Utilization .....................................................52
Caloric Efficiency.............................................................................53
Dressing percentage and carcass yield ......................................54
Economic Analysis..........................................................................54
Study 2. Effect of different cassava and copra meal levels in diet
from 1 to 21 day of age on production performance, caloric
efficiency and carcass characteristics of F1 (male Mia × female
Luong Phuong) chicken .....................................................................56
Growth Performance ......................................................................56
Efficiency of Crude Protein Utilization .........................................61
There were no (P>0.05) cassava × copra meals levels
interaction for any of the crude protein untilization parameters
measured (Table 11). .....................................................................61
From 1 to 21 day of age, chicks fed with increasing
concentrations of cassava meal had trend (P=0.07) and linear
reduced crude protein daily intake (Table 13). Chicks fed with
increasing of copra meal concentrations showed significant

difference (P<0.01) in crude protein daily intake. Crude protein
daily intake of chicks decrease linear and quadratic (P<0.05) in
progression copra meal in diets. ..................................................62
There were (P<0.05) significant differences in CP:BW gain
when chicks were fed from 0, 5, 10 and 15% cassava meal in
diets. Progressive cassava meal concentrations showed linear
increase (P<0.01) in CP:BW gain from 1 to 21 day of age
(Table 13). Chicks fed gradient concentrations of copra meal
were significant difference in CP:BW gain from 1 to 21 day of
age. Linear and quadratic were significant (P<0.05) increases
for CP:BW gain from 1 to 21day of age. There was no
viii


significant (P<0.05) between treatments without and 5% copra
meal in diet. ......................................................................................62
Caloric Efficiency.............................................................................63
Dressing Percentage and Carcass Yield ....................................64
Economic Analysis..........................................................................66
SUMMARY OF FINDINGS, CONCLUSIONS AND
RECOMMENDATIONS..........................................................................68
Summary of Findings .........................................................................68
Conclusions .........................................................................................70
BIBILOGRAPHY .....................................................................................73
...................................................................................................................82
APPENDIX OF TABLE ..........................................................................83
CURRICULUM VITAE..........................................................................119

LIST OF TABLES

Table

Page

1

Ingredients of nutritional value for chicken experiments period
1 to 21 of age

39

2

Ingredients of nutritional value for chicken experiments period
1 to 21 of age

41

3

Effect of varying ME to CP ratios on growth performance from
d 1 to 21 of age

50

4

Overall growth performance of broilers fed with varying ME to
CP ratios from d 1 to 21 of age

51

5

Effect of different energy to crude protein ratios on daily protein
intake and efficiency of protein utilization of chicken

52

6

Effect of different energy to crude protein ratios on daily ME
intake and efficiency of ME utilization of chicken

52

ix


7

Effect of different energy to crude protein ratios on carcass

53

8

Economic analysis

54

9

Effect of varying cassava meal and copra meal levels in diets
on growth performance from d 1 to 21 of age

56

10

Overall growth performance of broilers fed with varying
cassava meal and copra meal levels in diets from d 1 to 21 of
age

58

11

Effect of varying cassava meal and copra meal levels in diets
on daily protein intake and efficiency of protein utilization of
chicken

61

12

Effect of varying cassava meal and copra meal levels in diets
on daily ME intake and efficiency of ME utilization of chicken

63

13

Carcass characteristics of chickens fed varying cassava and
copra meals levels diets from day 1 to 21 of age

65

14

Economic analysis

67

LIST OF FIGURES
Figure

Page

1

The conceptual Paradigm of Studies

2

Experimental layout of Study 1

36

3

Experimental layout of Study 2

36

x

6


1

Chapter 1
THE PROBLEM AND ITS BACKGROUND

Introduction
Poultry production of Viet Nam has been continued significantly
growing at an average of 2.5 % per annum in the last 5 year with about 327.7
million heads in 2014. The meat of poultry was obtained as the second
largest meat sector with 642.5 thousand metric tons (MT) (GSO, 2015).
Significant developments in genetics, management, health and nutrition are
largely responsible for the rapid growth experienced today (Van et al., 2015).
Predilection for using native chicken, hybrid/color chicken of Vietnamese
consumer has induced the amount of these that always accounts for high
percentage in population (Van et al., 2015a). Native chicken such as Ri, Mia,
Ho, Dong Tao etc; color Luong Phuong, Tam Hoang, Kabir, SASO chicken
and hybrid comprise the most popular in semi intensive system in
smallholders of Viet Nam. These groups of chicken account for about 70%
of poultry population (GSO, 2015) but nutrient research for them was
unsystematic. Therefore, no nutrient specification apply for these groups.

Nutrition requirement for native chicken, color chicken and their hybrid were
applied from other group chicken which are found to be incorrect.
Bird responses of economic interest, such as body weight (BW) gain,
feed conversion ratio (FCR) and breast meat yield (BMY) depend on protein
content and biological value (BV) of protein (Mohsen et al, 2012; Vieira et al,
2012). Protein accounts for 20% of body weight of poultry, 16% of egg weight
and more than 1/3 protein in dry matter of animal bone. Therefore, protein is


2
an essential constituent of all tissues of animal body and has major effect on
growth performance of the bird (Jafarnejad et al, 2010; Mohsen et al, 2012).
Since all living tissue is in a dynamic state and is undergoing constant
degeneration, protein is also necessary for its maintenances (McDonal et al.,
1995; Tilden et al, 2000). Beside, birds need energy for every action (flying,
jumping, growing etc) (Jafarnejad et al, 2010) that alter material energy.
Excess metabolizable energy (ME) requirement of body is reserved as
animal fat (McDonal et al., 1995; Tilden et al, 2000). Metabolizable energy
with low density in the diet makes poultry to eat more; but feed consumption
is reduced if feeds are rich in energy. Therefore, the level of energy in the
diet must be balanced with other nutrients such as crude protein, essential
amino acids, and minerals to meet all feed requirements (Leeson and
Summers, 2009)
Previous researches have been conducted to estimate ME to CP ratio
of color chicken from 1 to 70 day of age (Van et al., 2016) but information is
limited for ME to CP ratio of native, color chicken and their cross during the
starter period (1 to 21 days). Whereas, Holsheimer and Ruesink (1993); Kidd
et al (1998) suggested that the quality of diet in earlier feeding phases may
have carryover effects on growth performance and carcass composition.
Leeson and Summers (2009) indicated that a 1 g difference in day 7 body

weight will be multiplied to 3 g at day 18 and 5 g at day 49.
Cassava meal contain 60 to 80% starch on dry matter (DM) of its
composition was considered as potential ingredient. However, cassava was
restrictedly used in diets because of poor protein and essential amino acids
content (Morgan and Choct, 2016). Copra meal is the by-product of oil


3
extraction of the endosperm of coconut. This byproduct is rich in protein (1525%) and carbohydrate (60%) (Sundu and Dingle, 2009). While its inclusion
in poultry diets is limited due to low levels of several essential amino acids,
in particularly lysine and total sulfur containing amino acids (Moorthy and
Viswanathan, 2010). To deal with this problem, it could be alleviated by
increasing soybean meal (SBM) in the diet or supplement synthetic amino
acids in the diet (Sundu and Dingle, 2009; Morgan and Choct, 2016). There
is, however, limited data to support this hypothesis.
Background of the Study

Mia chicken is raised in the Son Tay district, Ha Tay province. Mia
breed chicken was characterized by colors, almost roosters’ feather were
reddish-brown, and light yellow for female. Mia chicken breed has yellow
feet, yellow skin but red breast skin and single red cock’s comb. For these
characteristics, Mia chicken was offered to worship material in traditional
custom of Vietnam, especially lunar New Year, anniversary of ancestor’s
death.
Mia breed has a good resistance even in poor nutrition condition. This
breed consistence with cultural practices and farming methods and

high quality. The live weight of Mia chicken is 800–900 g at 60 days old and
3500–4.000 g and 2500–3000g for cocks and hens at 140–150 days,
respectively. They lay 55–60 eggs per hen per year (Van et al., 2015). For

these advantages therefore Mia chicken breed was used as male line in
cross with other breed. At present, the Mia breed population is very limited,
at risk of extinction and in need of conservation. To use the genetic resource


4
of this breed, it is necessary to identify the performance and breeding values
for selection and multiplication (Long et al., 2008).
Luong Phuong is one of these chicken breeds from China. It was
imported to Viet Nam from 1990. Luong Phuong chicken breed has yellow
feathers, yellow feet, red single comb and strong resistance. The live weight
of Luong Phuong chicken is 1500 g at 70 days old and 2000 - 2100 g and
2300 – 2400 g for adult cocks and hens, respectively (Van et al., 2015). This
breed is unlike SASSO breed chicken, its body weight is not very high at day
harvest which suitable for party of Vietnam. These characteristics were
almost the same native chicken therefore as from imported to Vietnam this
breed has liking for raiser. Average egg productive per hen per year of Luong
Phuong was 150 – 170 eggs (Van et al., 2015). For this feature and growth
performance of this breed which was used as female trait in crossing with
other native chicken of Vietnam to combine advantages of sire and dam.
Some studies on this breed show that it has good adaptability and are well
developed in Viet Nam (Dat and Tung, 2007). These breeds were highpriced, stable and suitable to the taste of customers thanks to their high
adaptability, consistence with cultural practices and farming methods and
high quality. Performance of crossbreds of local and exotic breeds is similar
to the average of their parents, but they are easier to feed and produce better
quality of meat. Through heterosis, crossbreeds have 2–13 percent greater
live weight at slaughtering compared to the average of their parents (Long et
al., 2008; Tung and Hao, 2010). Thus, since 1990, some households have
raised this crossbred to produce meat.

5
In poultry production, feed cost account for 70 - 80% of production
cost (Van et al., 2015) thus utilization local ingredient in diet is one method
to reduce production cost. Cassava is one of these local feedstuff in Viet
Nam. Cassava (Manihot esculenta Crantz), a tropical root crop which is
widely cultivated in Viet Nam, has great potential as a starch source for both
human and animal consumption. Cassava yield of Viet Nam estimated up to
9.7 million metric tons (GSO, 2015) a potential carbohydrate for human and
animal feed. The use of cassava as animal feed is not new. In tropical Africa
the peels are used as feed for ruminants (Eruvbetine et al., 2003). Many
studies have been undertaken to evaluate replacement of cereals with
cassava meal in poultry feeds. The results of these studies have yielded wide
variation in feeding value, nutritional problems, and productive performance.
The maximum level of cassava root meal in broiler diets has ranged. This
variation has been due to differences in many factors that will affect its
inclusion in poultry diets, such as anti-nutritional factors, cassava root
processing methods, and nutritional and physical factors (Eruvbetine et al.,
2003)
The production of copra meal in some parts of the world is abundant
and cheap hence its inclusion in poultry diets would benefit the poultry
industry. Its use as feeding material would also be beneficial for the coconut
industry and the environment, through the reduction of copra waste.
However, the nutritional and physical qualities of this by-product are poor,
and consequently, there has been limited use of this material in poultry diets.
Attempts to improve the quality of this feedstuff have been made through


6
supplementation with amino acids and enzymes as well as physical

treatments such as pelleting, soaking and grinding (Sundu et al., 2006)

Theoretical Framework of the Study
This dissertation consists of 2 studies. Study 1. Effect of ME to
protein rations in diet from 1 to 21 day of age on production performance
and carcass characteristics of F1 (Mia × Luong Phuong) chicken. Study 2.
Effect of different cassava and copra meal levels in diet from 1 to 21 day of
age on

production

performance,

caloric

efficiency

and

carcass

characteristics of F1 (male Mia × female Luong Phuong) chicken.

Conceptual framework of the study
The conceptual paradigm of the studies is shown in Figure 1.
The independent variables include the ME to protein ratios, different levels
of cassava meal and copra meal. The effect of which were determined on
the performance of the chickens and compared with the effects of other
treatments. These include different parameters presented in the dependent
variable, such as percent livability, body weight (g), average daily feed intake

(g), average daily gain (g), feed conversion ratio, carcass yield, crude protein
utilization, caloric efficiency and income over feed cost.


7
Study 1
Independent Variables
Feed day 1 – 21
(ME/CP ratios, Kcal/100 gr)

Dependent Variables
Performance at 84 days of age

1. 150.0 (2850/19)

1. Livability, %

2. 142.5 (2850/20)

2. Body weight, g

3. 135.7 (2850/21)

3. Average feed daily intake, g

4. 129.5 (2850/22)

4. Average daily gain, g

5. 123.9 (2850/23)

5. Feed Conversion Ratio
6. Carcass yield, %
7. Crude protein utilization
8. Caloric efficiency

Study 2
Independent Variables
Diets day 1 – 21
 Cassava meal levels
1. 0 % (Control)

3. Average feed daily intake, g

3. 10%

4. Average daily gain, g

4. 15%

 Copra meal levels
1. 0 % (Control)

3. 10%

1. Livability, %
2. Body weight, g

2. 5%

2. 5%

Dependent Variables
Performance at 84 days of age

5. Feed Conversion Ratio
6. Carcass yield, %
7. Crude protein utilization
8. Caloric efficiency

4. 15%

Figure 1. The conceptual Paradigm of Studies


8
Statement of the Problem
These studies aimed to evaluate the effect of feed materials: ME to
protein ratios, cassava meal levels, copra meal levels on the growth
performance and carcass yield of hybrid native chickens in Viet Nam.
Specifically, these aim to answer the following problems:
1.

What is the effect of ME to protein ratio on the performance, efficiency
of crude protein utilization, caloric efficiency, carcass characteristics,
economic of the (Mia × Luong Phuong) in terms of

2.

a.

Body weight;

b.

Body weight gain

c.

Average daily gain

d.

Average daily feed intake;

e.

Feed conversion ratio;

f.

Efficiency of CP utilization;

g.

Carcass yield;

h.

Economic analysis?

Is there a significant difference in the performance of the (Mia × Luong
Phuong) fed with diets containing difference ME to protein ratios?

3.

Is there significant difference in the performance of the experimental
birds with respect to cassava meal and copra meal levels in terms of the
following variables?
a.

Body weight;

b.

Body weight gain

c.

Average daily gain

d.

Average daily feed intake;


9

4.

e.

Feed conversion ratio;

f.

Efficiency of CP utilization;

g.

Carcass yield;

h.

Economic analysis?

Is there significant interaction effect between the cassava meal and
copra meal level in the ration of the experimental birds in terms of
a.

Body weight;

b.

Body weight gain

c.

Average daily gain

d.

Average daily feed intake;

e.

Feed conversion ratio;

f.

Efficiency of CP utilization;

g.

Carcass yield;

h.

Economic analysis?

Hypothesis of the Study

The following hypotheses were tested:
1. There is no significant difference in the performance of the experimental
birds fed with ME to protein ratios in term of following variables: Body
weight, Body weight gain, Average daily gain, Average daily feed intake,
Feed Conversion Ratio, Efficiency of CP utilization, Carcass yield, and
Economic analysis?
2. There is no significant difference in the performance of the experimental
birds fed with diets containing difference cassava meal and copra meal

in diet in term of following variables: Body weight, Body weight gain,


10
Average daily gain, Average daily feed intake, Feed Conversion Ratio,
Efficiency of CP utilization, Carcass yield, and Economic analysis?

Significance of the Study

This dissertation provided the performance of chicken fed with
different diets based on ME to protein ratios to reduce environmental
pollutions. This dissertation showed the specification nutrition for hybrid of
(Mia × Luong Phuong) raised under Viet Nam condition.
In particular, it could benefit the following:
Farmers. The outcome of this study could provide additional
knowledge to the farmer on how to choose appropriate feed ration for native
hybrid chicken.
Agricultural Technicians. As concrete data in this study will provide
information on the nutritional requirement of native hybrid chicken for
formulator and native chicken raised in the community.
People of the academe. The results of this research could provide
knowledge to researcher, professor and students for reference.
Other researchers. This study may provide ready reference for
investigation in the field of animal nutrition.
Scope and Limitation of the Study

The experiments were conducted at Thai Nguyen city, Thai Nguyen
province, Viet Nam from July to November 2017.
These studies were focused on the performance of hybrid (Mia × Luong
Phuong) chicken in Viet Nam under complete confinement litter floor rearing

system in terms of body weight (BW), Average daily feed intake, Feed


11
Conversion Ratio, Efficiency of CP utilization, Carcass characteristics, and
Economic analysis
ME to Protein ratios, cassava and copra meal levels were used on the
ration of the F1 (male Mia × female Luong Phuong) chickens from Viet Nam
National Animal Husbandry Institute. Diets were in mash form
Definition of Terms

The following statements were used to operationally or conceptually
define terms used or mentioned in the study.
Average daily feed intake: Average daily gain was computed as the
feed consumption divided by the feeding period.
Average Daily Gain: This was computed as the gain in weight divided
by the feeding period.
Body weight gain: The gain in weight was determined by subtracting
the end of trial period body weight from the initial weight.
Body weight. This refers to weight of the experimental chickens
which was taken at the start (day-old) up to the end of the study (3 weeks).
This was expressed in grams.
Breast meat percentage. Breast meat percentage was calculated
based on formula: Total breast meat (meat without skin and bones) divided
by the dressed weight then multiplied by 100.
Caloric efficiency: This was determined based on the ratio between
total ME intake and total body weight gain (show in kilocalories per kilogram
of weight gain)

12
CP efficiency: This was determined based on the ratio between total
CP intake and total body weight gain (show in gram per kilogram of weight
gain)
Daily ME intake: This was determined by adding average daily feed
intake multiplied by the corresponding ME (expressed in kilocalories per bird)
Daily CP intake: This was determined by adding average daily feed
intake multiplied by the corresponding CP (expressed in gram per bird)
Dressed chicken. Fasting of bird was conducted for 8 h (Trevisan et
al, 2014), then weighed and dressed. Birds were killed by cutting the jugular
vein, scalded, plucked and eviscerated. The abdominal fat were removed
from the abdomen and gizzard and weighed immediately after evisceration
using a precision scale (0.1 g). From the eviscerated carcass, skinless and
boneless wing, thigh and drumstick were obtained and all cuts were weighed
on a precision scale (0.1 g). Carcass yield was calculated relative to the bird
BW at slaughter and expressed as a percentage.

Carcass yield, % =

Carcass weight, g
Live weight, g

x 100

Economic Analysis
Feed cost per broiler, value of gain per broiler, feed cost per kg gain, and
margin over feed cost were calculated for each treatment using the
following equations:
Feed cost per chick (VND)

= Total feed consumed × Price per kg of feed

Value of gain per chick (VND)

= Total weight gain × LW price per chick

Feed cost per kg of gain = Feed cost per chick ÷ Total weight gain
(VND/kg BW)
Income over feed cost (VND)
= Value of gain per chick – Feed cost per chick


13
Feed Conversion Ratio (FCR). It is an indicator of how efficient the
experimental birds are in converting the feed they consumed into meat. The
lower the value, the more efficient the birds are. Feed consumption of the
birds for each replicate was determined by subtracting the weight of the feed
left from the amount of feed offered. The average cumulative feed
consumption at each weighing was determined by dividing the cumulative
feed consumption by the number of birds per replicate.
Leg Meat Percentage. Leg meat percentage was computed by
dividing the leg meat weight (meat without skin and bones in both drumstick
and thigh) by the dressed weight then multiplied by 100.
Livability. The number of surviving birds for the whole duration of the
study was recorded. It was computed by dividing the number of surviving
birds by the initial number of birds. In case there was mortality on the middle
of the stage; body weight of the live birds, dead birds and remained feeds
was measured.
Percentage of Abdominal Fat. Fat surrounding the gizzard, extending
in the ischium and surrounding the bursa of fabricius, cloaca, as well as adjacent

abdominal fat was collected, weighed and divided by the dressed then
multiplied by 100.


14
Chapter 2
REVIEW OF RELATED LITERATURE AND STUDIES

Various references were reviewed by the researcher to determine
theories, concepts, principles, methodologies, and findings that are relevant
and helpful to the conduct of the study and will serve as support in the
discussion of the results.
Related Literature

Proteins are made of strings of amino acids that form chains known
as peptides. Protein is the basic structural material from which all body
tissues are formed. This includes muscles, nerves, skin, antibody,
connective tissues and vital organs, as well as blood cells, hair, hoof and
horns (McDonald et al., 1995, Kamran et al., 2008, Nawaz et al., 2006,
Elmutaz et al., 2014). Protein is essential for the animal’s growth and
development (Nahashon et al., 2007, Niu et al., 2009, Pesti, 2009). It
accounts for 20% of body weight of poultry, 16% of egg weight and more
than 30% protein in the dry matter of animal bone (Van et al., 2015) Since
all living tissue is in a dynamic state and is undergoing constant
degeneration, protein is necessary for maintenance (Rostagno et al., 2011).
Body enzymes and hormones are protein in composition, which are both
regulators of catabolism and control metabolism (Sleman et al, 2015).
Protein is also a component of immune body which controls pathogens that
invade the body (Perween et al., 2016). When amino acids are available in
excess of the animal’s requirements or when the animal is forced to

catabolize body tissue to maintain essential body process, amino acids may


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be broken down to provide energy (Kamran et al., 2004). Therefore, poultry
can adjust protein to compensate for energy whereas carbohydrate and
lipids cannot be converted to protein.
Since proteins have been shown to be composed of individual amino
acids, the dietary crude protein (CP) requirement for monogastric animals is
the requirement of each of the amino acids per se. From the information of
protein synthesis. For poultry species, 19 amino acids in body proteins and
all of them are physiologically essential to the birds (D’Mello, 2003; Kidd and
Tillman, 2016). Nutritionally, these amino acids can be divided into three
categories: (1) EAA: Arg, His, Ile, Leu, Lys, Met, Phe, Thr, Trp and Val; (2)
Semi–essential AA: Cys, Gly, and Tyr; and (3) Non-essential AA: Ala, Asp,
Glu, Pr) and Ser
The ideal protein concept has been using lysine as the reference
amino acid even though methionine has been shown to be the primary
limiting amino acid. Lysine was selected as the reference amino acid for the
following reasons: 1) lysine is the second limiting amino acid (in most
commercial poultry diets and the supplementation is economically available;
2) the analysis of lysine is a relatively simple procedure; 3) dietary lysine is
utilized only for protein accretion and maintenance of broiler chicks; 4) there
are a number of research projects conducted to determine the lysine
requirements of different broiler strains under various conditions (Emmert
and Baker, 1997).
Several things shape the ideal protein concept: 1) increasing concerns
about environmental impacts such as nitrogen and phosphorus pollution
resulting from animal production; 2) available sophisticated feed formulation