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


ABSTRACT

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
...................14

RELATED

LITERATURE

AND

STUDIES

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
52 intake and efficiency of protein utilization of chicken

6

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

ix

52


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

12

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

13


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


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


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 high- priced, 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.


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


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.


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

Dependent Variables
Performance at 84 days of age

1. 0 % (Control)

1. Livability, %

2. 5%

2. Body weight, g

3. 10%

3. Average feed daily intake, g

4. 15%

4. Average daily gain, g

 Copra meal levels
1. 0 % (Control)
2. 5%
3. 10%

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

8. Caloric efficiency

4. 15%

Figure 1. The conceptual Paradigm of Studies


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;


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,


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


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)


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