Năng suất sinh sản của lợn nái có 1 4 giống VCN MS15 và sức sản xuất thịt của một số tổ hợp lợn lai có 1 8 giống VCN MS15 ở tỉnh thừa thiên huế TT tieng anh

HUE UNIVERSITY
UNIVERSITY OF AGRICULTURE AND FORESTRY

NGUYEN XUAN AN

STUDY ON REPRODUCTIVE PERFORMANCE OF SOWS
WITH 1/4 VCN-MS15 BREED AND PORK PRODUCTIVITY OF
SOME CROSSBRED GENOTYPES WITH 1/8 VCN-MS15 BREED
RAISED IN THUA THIEN HUE PROVINCE

Major:

Animal Sciences

Code:

9620105

\

SUMMARY OF PHD THESIS IN AGRICULTURAL SCIENCE

HUE, 2020


This work was completed at:
University of Agriculture and Forestry, Hue University

Supervisors
1. Assoc.Prof. Dr. Phùng Thăng Long
2. Prof. Dr. Lê Đình Phùng

Reviewer 1: ………………………………………………………………………
Reviewer 2: ………………………………………………………………………..
Reviewer 3: ………………………………………………………………………..

The thesis was defended in front of thesis assessment committee of Hue University:
Venue: 4 Le Loi street, Hue City, Thua Thien Hue province, time…….. on ……/
……./20

Thesis can be found at:
1. National Library
2. Department of Science, International Relations, Information and Library of
University of Agriculture and Forestry, Hue University


1

INTRODUCTION

1. BACKGROUND
In the world and in our country, animal crossbreeding has been widely used and is seen
as a very effective solution to improve pork productivity and quality. This solution helps to
minimize the disadvantages and maximize the advantages of each breed. In addition, the use
of crossbred sows and suitable boars for mating with sows are important in providing
compensatory effects and heterosis in offsprings (Jiang et al., 2012).
The Meishan pig breed is well-known pig breed in the world for its ability to give birth
and have many piglets. In China, Meishan pigs are widely used as breeding sows or
crossbred sows to improve reproductive performance, and crossbred with exotic boars such
as Landrace, Duroc to produce commercial hybrids 2 or 3 breeds with improved carcass
yield and good meat quality. Some recent studies have shown that the commercial
crossbreeds with 1/8 Meishan breeds improved meat yield and quality (Jiang et al., 2012).

Many countries around the world such as the UK, France, the US... have used the
Meishan breed to improve the fertility of the sow herd through exploiting the maternal
crossbred dominance in hybrid combinations.
In Vietnam, since 1997, the breeding pig farm Tam Diep (Ninh Binh) has used the L95
synthetic Meishan pig line derived from PIC (The Pig improvement Company) to cross with
the male line L06 to create the Grandparents C1230 line, and crossbred with L19
synthesized boars to produce CA breeding females to produce commercial crossbred pigs
with 5 breeds with high yield and good pork quality and used in the Northern provinces and
some central provinces of Vietnam.
In 2010, Thuy Phuong Pig Research Center conducted a trial of Meishan pig breed and
concluded: this breed was adapted and suitable for livestock conditions in Vietnam (Trinh
Hong Son et al., 2012), and recognized by the Ministry of Agriculture and Rural
Development (MARD), a new breed of pig named VCN-MS15 and allowed to produce and
trade in Viet Nam.
The research results on reproductive and growth performance, pork productivity and
quality of hybrid pigs with 1/2 and 1/4 VCN-MS15 breed raised by industrial model in Thua
Thien Hue province all showed good results (Le Duc Thao et al., 2015; Phung Thang Long
et al., 2015). However, How about reproductive performance of crossbred sows with 1/4
and meat productivity of crossbred pigs with 1/8 VCN-MS15 breed? It is still an
unanswered question. Therefore, I have conducted a “Study on reproductive performance of
sows with 1/4 VCN-MS15 breed, and pork productivity of some crossbred genotypes with
1/8 VCN-MS15 breed raised in Thua Thien Hue province”.


2
2. OBJECTIVE
This study aimed to determine reproductive performance of the sow with 1/4 VCNMS15 breed mated with Pietrain, Duroc boars, and growth, meat yield and quality of some
crossbred genotypes with 1/8 VCN-MS15 breed fed commercial feed under natural
conditions in Thua Thien Hue province in order to recommend managers and producers to
choose and apply suitable crossbred pigs with VCN-MS15 breed to improve reproductive

performances, and growth performance, pork yield and quality as well as economic
efficiency in pig production in Thua Thien Hue province and central Vietnam.
3. SCIENTIFIC AND PRACTICAL SIGNIFICANCE
3.1. Scientific significance
The research results of this dissertation contribute to scientific database on the sexual
physiology characteristics and reproductive performance of Landrace × (Duroc × VCNMS15) sows mated to Duroc boar and Landrace × (Pietrain × VCN-MS15) sows mated to
Pietrain boar; and the growth performance, pork yield and quality of crossbred pigs of
(Pietrain × [Landrace × (Duroc × VCN-MS15)], Duroc × [Landrace × (Pietrain × VCNMS15)], PIC280 × [Landrace × (Duroc × VCN-MS15)], and PIC399 × [Landrace × (Duroc
× VCN-MS15)]) fed with commercial feeds under natural conditions in Thua Thien Hue
province.
3.2. Practical significance
The study has shown that the crossbred sows with 1/4 VCN-MS15 breed had high
reproductive performance. Crossbred pigs with the 1/8 VCN-MS15 breed had high growth
performance, with normal meat quality, and suitable for development in Thua Thien Hue
province. These are new scientific documents that serve as the basis for recommending
commercial pig production with the participation of VCN-MS15 breed.

Chapter 1
LITERATURE REVIEW
1.1.

RESEARCH AND APPLICATION OF PIG CROSSBREEDING
ENHANCING PRODUCTIVITY IN THE WORLD AND IN OUR COUNTRY
1.1.1. In the World
1.1.1.1. Improving reproductive performance of sows

TO

Genetic improvement of sow reproductive performance can be achieved by selecting
purebred or crossbred breeds. However, most of the pig's reproductive performance have

low genetic coefficients, so it is difficult for the selection to achieve high results. Therefore,
breeding is the fastest way to increase the number of piglets per litter. This is a method used
to combine desirable traits of two or more breeds or pig lines to take advantage of hybrid


3
advantages. Breeding different breeds in pigs is applied to enhance fertility to alter the
genetic structure of the population to exploit hybrid dominant characters.
In countries with developed animal husbandry, depending on the needs of the
consuming market, different breeding production systems are determined. For example, in
Denmark, France, Spain,... the pork consumption market is mainly for the world market, the
production of commercial pigs is based on crossbreeding of three breeds based on Landrace
and Yorkshire sows. Whereas three Nordic countries (Norway, Finland and Sweden), two
breeds of pigs, Yorkshire and Landrace, are mainly used for the production of hybrid sows
(Hansson, 2003). In China, which is the largest pig breeding country in the world, F1 hybrid
sows (Landrace × Yorkshire) are quite common (Xue et al., 2018).
1.1.1.2. Improving growth performance and meat quality
Changes in the pork industry are occurring worldwide. Intensive pig production
system and increased yield and lean percentage have reduced sensory meat quality.
Research carried out in recent years has demonstrated that sensory meat quality is related to
a percentage of Longissimus dorsi fat and other characters such as water holding capacity
and meat pH (Przybylski et al., 2010). However, the increase in the percentage of fat in the
Longissimus dorsi affects the health of the consumer. For the pork industry to be successful,
it means meeting consumer expectations. Recent studies have been conducted not only on
performance but also on meat quality.
1.1.1.3. Research and application of the Meishan breed
One of the Chinese pig breeds that has received the most attention over the years is the
Meishan breed. Meishan pigs have been crossbred with modern pigs and then selectively
synthesized lines over many generations based on the phenotypic values on the fertility,
growth and meat quality measurements studied. The crossbreeding program has shown that

the highest heterosis in F1 generation when using Meishan pig breed with modern pigs to
exploit hybrid dominant characters in reproductive performance and fertility traits. For
example, the number of alive piglets per litter was not different from pure Meishan or even
higher.
In China, Meishan pigs are commonly used as breeding sows or cross-breeding sows
to crossbred with exotic boars such as Landrace or Duroc to produce commercial 2, 3 breeds
with improved carcass traits and good meat intake (Jiang et al., 2012). The Meishan pig
breed is also used as a material for breeding new breeds.
1.1.2. In Viet Nam
1.1.2.1. Improving reproductive performance of sows
Application of crossbreeding to improve sow reproductivity is quite popular in
industrial livestock production in our country. A number of different hybrid combinations
have been created for each stage of the livestock industry's development and specific to
different regions of the country. The formulas of crossbreeding between exotic boars and
domestic sows, between exotic and exotic pig breeds have been widely researched and have
made many positive contributions to improving reproductive productivity in pig farming in


4
our country. Many combinations of
reproductive results.

2 and 3 breeds for breeding sows gave good

In the North, the cross between two exotic breeds with domestic or foreign pigs has
been carried out since 1960. Two usual breeds used are Landrace and Yorkshire and the
popular domestic breed is Mong Cai. Until now, F1(Landrace × Yorkshire) or F1(Yorkshire ×
Landrace) and F1(Yorkshire × Mong Cai) or F1(Landrace × Mong Cai) sows were quite
popular sows in domestic pig production.
Many studies showed that the reproductive performance of crossbred sows

F1(Landrace × Yorkshire) or F1(Yorkshire × Landrace) raised in industrial or semi-industrial
conditions is mated with different boar strains gave good performance (Nguyen Ngoc Phuc
et al., 2009; Le Dinh Phung, 2009; Le Dinh Phung and Dau Thi Tuong, 2012; Le Dinh
Phung et al., 2011).
1.1.2.2. Improving growth performance and meat quality
Currently, the market demand for high quality pork is increasing, so research to
improve meat quality is being interested. Productivity and pork quality traits depend on
cross breeding. Therefore, there have been many studies on meat yield and quality on
different crossbreds with 2, 3, 4 and 5 different breeds which are quite popular in the
industrial pig industry in our country.
Growth performance of growing crossbred pigs
When assessing the growth performance of commercial crossbred pigs on F 1(Yorkshire
× Landrace) sows in Ha Nam and Hai Duong, Ngo Thi Kim Cuc and Nguyen Van Trung
(2018) showed that the average daily gain (ADG) of commercial pigs was highest in the
group using Duroc × (Pietrain × Duroc) (760.21 g/day) then followed by the F 1(Duroc ×
Pietrain) (754.13 g/day) and lowest in the group using F1(Duroc × Landrace) (729.45 g/day).
The feed conversion ratios (FCR) of the Duroc × (Pietrain × Duroc) and the F 1(Duroc ×
Pietrain) were the lowest (2.61 and 2.65) and the F 1(Duroc × Landrace) was the highest at
2.74.
Recently, PICs of PIC group like PIC399, PIC280 (USA group) have been imported
and initially used in some industrial pig farms in our country. These lines excel in ADG and
low FCR. Research results of Le Dinh Phung et al (2015) showed that the combination of
crossbred PIC280 × (Landrace × Yorkshire) pig and PIC399 × (Landrace × Yorkshire) pig
during 60 to 150 days old, with ADGs were 765 g/day and 879 g/day, respectively, and
FCRs 2.74 and 2.61, respectively.
Meat production and quality of growing crossbred pigs
The results of Nguyen Van Thang and Vu Dinh Ton (2010) showed that the dressing
percentage, carcass and lean percentages of crossbred pigs with 4 breeds as PiDu ×
(Landrace × Yorkshire) pigs is higher than that with 2 and 3 breeds as Landrace × (Landrace
× Yorkshire), or Duroc × (Landrace × Yorkshire) and the pork quality of these crossbred

pigs are normal.


5
Le Dinh Phung et al (2015) reported that crossbred pigs PIC280 × (Landrace ×
Yorkshire) and PIC399 × (Landrace × Yorkshire) have superior pork yield compared to
some popular crossbreds today. The fat content in the loin of PIC280 × (Landrace ×
Yorkshire) pig (2.62%) was higher than that of PIC399 × (Landrace × Yorkshire) pig
(1.49%), while the meat quality characteristics of the two studied crossbred pigs were in the
normal meat range.
Thus, in recent years, there have been many publications evaluating quite
comprehensive meat yield and quality in pig breeding programs with the last male breeds
such as Pietrain, Duroc, PiDu,... have contributed partly to improving productivity, quality
of meat and diversifying pig breeds in the pig industry in our country.
1.1.2.3. Research and application of Meishan breed
With the aim of exploiting the precious genetic capital of Meishan pigs for
crossbreeding groups of crossbred sows and new hybrid pigs with competitive production
capacity and further, new breeding. In 2010, Thuy Phuong Pig Research Center carried out
adaptive farming of pigs with Meishan genetic resources from the DA15 project. The results
of research on physiological characteristics and testing of Meishan pig breed showed that
this breed was adapted and suitable for livestock conditions in Viet Nam (Pham Duy Pham
et al., 2014; Trinh Hong Son et al., 2012). With this result, the MARD recognized the
Meishan pig genetic source as a new breed called VCN-MS15 and allowed to produce and
trade in Viet Nam. Over the past 10 years, the breed VCN-MS15 has been studied with
different VCN-MS15 breeds for high reproductive performance, good growth, high lean
percentage and reduced back fat thickness.

Chapter 2
CONTENTS AND METHODS
MATERIALS, CONTENTS AND RESEARCH METHODS

2.1. MATERIALS
- Crossbred sows with 1/4 VCN-MS15 breed including: Landrace × (Duroc × VCNMS15) (LDM) sows mated with Pietrain boars and Landrace × (Pietrain × VCN-MS15)
(LPM) sows mated with Duroc boars.
- Commercial crossbred pigs with 1/8VCN-MS15 breed including: Duroc × [Landrace
× (Pietrain × VCN-MS15)] (DLPM), Pietrain × [Landrace × (Duroc × VCN-MS15)],
PIC280 × [Landrace × (Duroc × VCN-MS15)] (PIC280LDM) and PIC399 × [Landrace ×
(Duroc × VCN-MS15)] (PIC399LDM) pigs.

2.2. RESEARCH CONTENTS
Initially, evaluating the reproductive performance of crossbred sows with 1/4
VCN-MS15 breed, including: LPM sows were mated with Duroc males and LDM
sows were mated with Pietrain males.


6

Researching the growth capacity, meat productivity and quality of the DLPM
and PLDM crossbred pigs.
Researching the growth capacity, meat productivity and quality of the
PIC280LDM and PIC399LDM crossbred pigs.
2.3. STUDY’S PLACE AND TIME
- Place: (i) Reproductive performance of LPM sows mated with Duroc and LDM sows
mated with sows Pietrain were conducted at the Institute of Biotechnology, Hue University;
(ii) Study on growth, meat yield and quality of crossbred pigs with 1/8 VCN-MS15 (DLPM,
PLDM, PIC280LDM and PIC399LDM) were conducted at the facility of the Institute of
Biotechnology, Hue University; (iii) The meat quality measurements were analyzed at the
Laboratory of Department of Animal Genetics and Breeding, Faculty of Animal Sciences
and Veterinary Medicine, University of Agriculture and Forestry, Hue University; (iv) The
fatty acid composition of the longissimus dorsi muscle was analyzed at Eurofins Sac Ky Hai
Dang Co., Ltd. - Floor M, 141 Nguyen Du, Ben Thanh Ward, District I, Ho Chi Minh City.

- Time: The studies were conducted from June 2015 to September 2018.
2.4. METHODS
2.4.1. Sexual physiological characteristics and reproductive performance of sows have
1/4 VCN-MS15 breed
2.4.1.1. Experimental design 1
A total of 16 female pigs with 1/4 VCN-MS15 breed, including: 08 LPM females and
08 LDM females to ensure uniformity are fully vaccinated according to regulations. In the
gilt-stage, pigs are raised 4 heads/pen, freely fed commercial feed, and raised in an open
industrial house until the first heating. After that, pigs were raised individually.
2.4.1.2. Sexual physiological characteristics and reproductive performance of sows with
1/4 VCN-MS15 breed
- Traits for evaluating sexual physiological features: First estrus age (day), age at first
mating (day); age at first farrowing (day); weight at first estrus (kg); weight at first mating (kg).
- Traits for reproductive performance evaluation: Number of newborn piglets
(head/litter); number of piglets alive up to 24 hours (head/litter); number of alive piglets up
to 21 days old (head/litter); number of alive piglets to wean (30 days old) (head/litter); rate
of raising piglets to wean (%); weight of newborn piglets (kg/head); the weight of 21 days
old piglets (kg/head); weight of piglets weaned at 30 days of age (kg/head); mother pig
body wear rate (%); time of back in heat (days); pregnancy period (days); number of
litters/sow/year; number of piglets weaned/sow/year, weight of piglets weaned/sow/year
(kg).
2.4.2. Growth performance, pork yield and quality of the DLPM and PLDM pigs
2.4.2.1. Experimental design 2


7
Table 2.1. The 2nd experimental layout
Pig breed
Number (head)

DLPM
16 (8 M, 8 F)

Keeping time (60-160 days old)
Farming regime

100

PLDM
16 (8 M, 8 F)
100

Individual

Individual

Feeding and water drinking

Ad lib

Ad lib

Type of pig house

Open

Open

6 (3 M, 3 F)

6 (3 M, 3 F)

Number of slaughter pigs

2.4.2.2. Growth performance
Initial live body weight (kg); age at start of experiment (date); weight of pigs over the
experimental months (kg); average daily gain (g/head); feed intake (kg/head/day); feed
conversion ratio (FCR).
2.4.2.3. Carcass characteristics and meat quality
- Carcass characteristics: slaughter body weight (kg); hot dressing weight (kg); carcass
weight (kg); dressing percentage (%); carcass percentage (%); back fat thickness at P2 (cm);
loin muscle area at the rib number 10-11 (cm2); lean percentage (%); carcass length (cm).
- Meat quality measurements: pH value, tenderness (N), storage water loss rate (%),
processing water loss rate (%) and meat color (L*, a*, b*) of the loin muscle at the rib 1014th.
- Chemical composition of the loin muscle: Dry matter (%);Crude protein (%); Ether
extract (%);Total ash (%); and fatty acid composition.
2.4.3. Growth performance, meat yield and quality of PIC280LDM and PIC399LDM pigs
2.4.3.1. Experimental design 3
Table 2.2. The 3rd experimental layout
Pig breed
Pig number (head)

PIC280LDM
18 (9 M, 9 F)

PIC399LDM
18 (9 M, 9 F)

90

90

Individual

Individual

Feeding and water drinking

Ad lib.

Ad lib.

Type of pig house

Open

Open

6 (3 M, 3 F)

6 (3 M, 3 F)

Time for keeping (60-150 days old)
Farming regime

Number of slaughter pigs


8
2.4.3.2. Growth performance

The measurements and research methods for the growth performance, meat yield and
quality of the two crossbred PIC280LDM and PIC399LDM pigs in the 3 rd experiment were
similar to those described in the 2nd experiment.
2.5. DATA ANALYSIS
Data are entered and managed on Microsoft Excel software (2010) and analyzed by
specialized software MINITAB 16.2 (2010). The results presented in the tables are the mean
± standard error of the mean (Mean ± SE). The mean values were considered to be
significantly different when P<0.05.


9
Chapter 3
RESULTS AND DISCUSSION
3.1. SEXUAL PHYSIOLOGICAL CHARACTERISTICS AND REPRODUCTIVE
PERFORMANCE OF LPM AND LDMFEMALES
3.1.1. Sexual Physiological characteristics
The results on sexual physiological characteristics of female pigs of the LPM and
LDM are presented in Table 3.1.
Table 3.1. Sexual physiological characteristics (Mean ± SE)

First estrus age (day)

LPM
(n = 8)
146.50 ± 0.93

LDM
(n = 8)
145.40 ± 1.16

>0.05

Live weight at first estrus (kg)

88.40 ± 0.89

84.10 ± 1.23

>0.05

Age for first mating (day)

186.10 ± 0.72

187.00 ± 2.73

>0.05

Live weight at first mating (kg)

116.60 ± 1.21

110.70 ± 1.58

>0.05

Age of first farrowing (day)

299.50 ± 0.66

301.40 ± 2.71

>0.05

Items

-

P

Age and live weight at first estrus

Age and weight of first estrous of LPM and LDM female pigs were not statistical
difference (P>0.05). First estrous age and weight of LPM and LDM pigs in this study
ranged from 145.40 - 146.50 days and 84.10 kg to 88.40 kg.
-

Age and live weight at first mating

Similar to the age and weight of first estrus, age and weight of first mating of LPM and
LDM female pigs were not statistically different, ranged from 186.10 to 187.00 days and
110.70 - 116.60 kg (P> 0.05)
-

Age of first farrowing

The age of first farrowing of the female pig is one of the important criteria, indicating
the age at which the female pig starts to exploit. The age of first farrowing of LPM and
LDM sows was 299.60 days and 301.40 days (P>0.05), respectively.
From the above results, it can be said that LPM and LDM sows have characteristics of

sexual maturity, age of first mating early which are earlier than some popular breeds today.
3.1.2. Reproductive performance of LPM and LDM sows
The results are presented in Table 3.2.


10
Table 3.2.Reproductive performance of the LPM and LDM sows (Mean ± SE)
Items

n

LPM

n

LDM

P

Average reproductive performance of 1-2nd parity
Number of new born piglets per litter
(head)
N of alive new piglets at 24hrsper
litter (head)
N of alive piglets at 21 days old per
litter (head)
N of piglets at 30 days old per litter
(head)

n

LPM

n

LDM

P

Ave. reproductive performance of 3-4th parity

16

12.21 ± 0.28

16

11.87 ± 0.31

>0.05

16

13.88 ± 0.34

16

13.50 ± 0.26

16

11.63 ± 0.20

16

11.44 ± 0.24

>0.05

16

12.94 ± 0.36

16

12.75 ± 0.23 >0.05

16

11.43 ± 0.20

16

11.31 ± 0.23

>0.05

16

12.31 ± 0.27

16

11.87 ± 0.22

>0.05

16

11.06 ± 0.20

16

11.00 ± 0.26

>0.05

16

11.87 ± 0.32

16

11.68 ± 0.18

>0.05

Survival rate at weaning (%)

16

95.16 ± 1.16

16

96.17 ± 1.38

>0.05

16

91.78 ± 2.04

16

91.66 ± 1.24

>0.05

LW* of born piglet (kg/head)

186

1.20 ± 0.02

183

1.17 ± 0.02

>0.05

207

1.26 ± 0.01

204

1.26 ± 0.01

>0.05

183

5.24 ± 0.06

181

4.97 ± 0.07

>0.05

197

5.32 ± 0.10

190

5.03 ± 0.10

>0.05

177

6.92 ± 0.07

176

6.79 ± 0.08

>0.05

190

7.10 ± 0.34

187

6.85 ± 0.13

>0.05

Lost percentage of sow live weight (%)

16

9.84 ± 0.24

16

9.76 ± 0.35

>0.05

16

9.29 ± 0.38

16

9.95 ± 0.22

>0.05

Return estrous after weaning (day)

16

5.00 ± 0.26

16

5.07 ± 0.27

>0.05

16

5.19 ± 0.21

16

4.94 ± 0.28

>0.05

Pregnant duration (day)

16

113.73 ± 0.21

16

114.07 ± 0.25 >0.05

16

113.81 ± 0.29

16

Number of litter per year per sow

16

2.40 ± 0.03

16

>0.05

16

2.40 ± 0.03

16

Weaned piglet LW/sow/year (kg)

16

184.56 ± 4.87

16

180.02 ± 4.30 >0.05

16

203.04 ± 7.25

16

LW of piglet at 21 days old
(kg/head)
LW of piglet at 30 days old
(kg/head)

*LW= live weight

2.41 ± 0.03

>0.05

113.38 ± 0.26 >0.05
2.38 ± 0.03

>0.05

190.56 ± 5.26 >0.05


11

- Number of piglets at born per litter
The average number of newborns per litter at parities 1-2 of LPM and LDM sows were
not statistically different, ranging from 11.87 to 12.21 (P>0.05). The number of newborn
piglets/litter increased in 3-4th parities (13.50 vs. 13.88), but there was no statistical
difference between LPM and LDM sows (P>0.05).
- Number of alive piglets and number of newborn piglets alive up to 21 days old
The data in Table 3.2 show that the number of alive piglets and the number of piglets
alive to 21 days of age of the two types of sows did not have a statistically significant
difference (P>0.05). However, these values are higher at parities 3-4 compared to parities 12. The number of survival piglets in parities 1-2 ranged from 11.44 to 11.63 and at 3-4 was
12.75 - 12.94; while the number of newborn piglets still alive for 21 days in parities 1-2 was
11.31 - 11.43; and 3-4 was11.87 - 12.31 piglets/litter.
- Alive piglet number at weaning per litter
The number of piglets still alive at weaning of the 2 types of crossbred sows with 1/4
VCN-MS15 breed did not differ significantly (P>0.05). But as a rule, these values for
parities 1-2 were lower than parities 3-4. The number of alive piglets to weaning/litter in
parities 1-2 ranged from 11-11.06 and the parities 3-4 was from 11.68 to11.87; Thus, the

average number of weaned piglets of 4 parities was 11.6 piglets.
- Survival rate of piglets to wean
The survival rate of piglets to wean from the sows with 1/4 th of VCN-MS15 breeds
was not statistically different (P>0.05). The rate of piglets alive to weaning of 2 groups in
parities 1-2 ranged from 95.16% to 96.17% and tended to be higher than that of parities 3-4
(91.66 - 91.78%).
- Live weight of newborn piglet, at 21 days old and at weaning of 30 days old
The weight of newborn piglets, the weight of piglets at 21 days of age and at
weaning at 30 days of age of the two groups of crossbred sows did not have statistically
significant differences (P>0.05). However, these values are higher at parities 3-4 compared
to parities 1-2, and at the same time the weight increases with days of raising. The weight of
newborn piglets in parities 1-2 fluctuates 1.17 - 1.20 kg/head and at parities 3-4 is 1.26 1.26 kg; while the weight of piglets at 21 days of age at parities 1-2 was 4.97 - 5.24 kg, at
parities 3-4 was 5.03 - 5.32 kg; weight at 30 days of age at parities 1-2 is 6.79 - 6.92 kg and
at parities 3-4 are 6.85 - 7.10 kg.
- Lost percentage of maternal live weight, time to return estrous after weaning and
litter number per year
The results of the maternal LW lost in this study ranged from 9.29 to 9.95%, which is
lower than the results of study of Wolter et al. (2000) , on the same sow type. This result in
Landrace × (Meishan × Yorkshire) sows (One quarter of the Meishan breed ) was 19.6% and
in Duroc × (Meishan × Yorkshire) was 16.5%.
The time to return to heating for LPM and LDM sows ranged from 4.94 to 5.19 days
(P>0.05); The number of litters/sow/year in two groups of sows with 1/4 VCN-MS15 breed


12

ranged from 2.38 to 2.41 and there was no statistical difference between the two crossbred
sow groups (P>0.05).
- Number of piglets weaned per year per sow
The number of weaned piglets/sow/year of the 2 groups of sow with 1/4 VCN-MS15

breed was not statistically significant and ranged from 26.51 to 27.79.
- Total weaned piglets live weight per sow per year
Total LW of piglets weaned/sow/year is an indicator of overall evaluation of
reproductive performance of the sow. In this study, total LW of piglets weaned/year of the
LPM sow reached 203.04 kg, higher than that (190.56 kg) of the LDM sow (P> 0.05).
The research results on sexual physiological characteristics and reproductive
performance indicators of LDM and LPM sows showed that the fertility was relatively high
compared to some common combinations of hybrid sows today.
3.2. GROWTH PERFORMANCE, PORK YIELD AND QUALITY OF DLPM AND
PLDM CROSSBRED PIGS
3.2.1. Live weight and daily weight gain
The results on live weight (LW) and average daily gain (ADG) are presented in Table
3.3.
Table 3.3.Live weight (and average daily gain during the experiment (Mean ± SE)
Item
Initial BW, 60 days old (kg/head)
LW at 90 days old (kg/head)
LW at 120 days old (kg/head)
LW at 150 days old (kg/head)
Final BW, 160 days old(kg/head)
ADG, 60-90 days old (g)
ADG, 90-120 days old (g)
ADG,120-150 days old (g)
ADG,150-160 days old (g)
ADG, whole period (g)

DLPM
(n = 16)
15.63 ± 0.36
32.00 ± 1.06

51.25 ± 1.18
70.25 ± 1.46

PLDM
(n = 16)
15.63 ± 0.56
33.63 ± 0,79
55.19 ± 1.00
77.75 ± 1.26

>0.05
>0.05
<0.05
<0.01

80.75 ± 1.59
545.80 ± 25.80
641.70 ± 24.20
656.20 ± 19.40
981.30 ± 16.40
651.30 ± 14.20

87.88 ± 1.19
600.00 ± 12.20
718.80 ± 18.90
752.10 ± 10.40
1012.50 ± 20.20
722.50 ± 7.16

<0.01

>0.05
<0.05
<0.001
>0.05
<0.001

P

Data in Table 3.3 shows that, the live weight at the end of the experiment (160 days
old) in 2 crossbred pigs with Pietrain male was higher than that of the Duroc boars (P<0.01).
Average daily gain during the whole experimental period, increasing ADG in the 1/8 VCNMS15 breed with the late Pietrain male than the Duroc (P <0.001).
3.2.2. Daily Feed intake and feed conversion ratio
The results on Daily feed intake (DFI) and feed conversion ratio (FCR) of pigs in
two groups are presented in Table 3.4.


13

Table 3.4. Daily feed intake and feed conversion ratio during
the experiment (Mean ± SE)
Item
DFI in 1st feeding month (kg/head)
DFI in 2nd feeding month (kg/head)
DFI in 3rd feeding month (kg/head)
DFI in 4st feeding month (kg/head)
Average DFI (kg/head)
FCR in 1st feeding month
FCR in 2nd feeding month
FCR in 3rd feeding month
FCR in 4st feeding month

Average FCR

DLPM
(n = 16)
0.98 ± 0.02
1.59 ± 0.02
1.96 ± 0.01
3.32 ± 0.11
1.69 ± 0.03
1.80 ± 0.06
2.48 ± 0.04
3.09 ± 0.09
3.16 ± 0.02
2.60 ± 0.03

PLDM
(n = 16)
1.01 ± 0.01
1.81 ± 0.06
2.21 ± 0.03
3.55 ± 0.08
1.86 ± 0.02
1.68 ± 0.02
2.51 ± 0.07
2.94 ± 0.13
3.05 ± 0.06
2.58 ± 0.04

P
>0.05

<0.01
<0.01
<0.05
<0.001
>0.05
>0.05
>0.05
<0.01
>0.05

Data in Table 3.4 showed that, the average feed intake during the experiment PLDM
was 2.15 kg/head/day, higher (P<0.001) compared to 1.96 kg/head/day in DLPM pigs. This
result showed that crossbred PLDM pigs had higher feed intake ability than DLPM pigs.
The average FCR during the experiment in the PLDM pig was 2.53, which tended to be
lower than 2.63 in the DLPM pigs but not significantly different (P>0.05). This result shows
that the two groups of commercial crossbed pigs, DLPM and PLDM have good feed
efficiency.
3.2.3. Carcass characteristics
The results on carcass characteristics crossbred pigs groups presented in Table 3.5.
Table 3.5.Carcass characteristics of DLPM and PLDM pigs (Mean ± SE)

Live weight at slaughter (kg)
Dressing weight (kg)

DLPM
(n = 6)
79.67 ± 2.85
63.13 ± 2.16

PLDM

(n = 6)
86.50 ± 2.31
68.13 ± 1.92

>0.05
>0.05

Dressing percentage (%)

79.27 ± 0.15

78.76 ± 0.46

>0.05

Carcass weight (kg)
Carcass percentage (%)
Carcass length (cm)
Backfat thickness at P2 (mm)
Loin area (cm2)

57.28 ± 1.97
71.92 ± 0.17
84.67 ± 1.54
9.60 ± 0.07
39.59 ± 1.97

62.30 ± 1.89
71.99 ± 0.50
87.50 ± 1.18

9.30 ± 0.16
41.58 ± 2.07

>0.05
>0.05
>0.05
>0.05
>0.05

Lean/carcass (%)

58.60 ± 0.67

59.29 ± 1.37

>0.05

Item

P

The criteria for slaughter weight, dressing weight, carcass weight, carcass length and
loin eye area in PLDM pig were 86.50; 68.13; 62.30 kg; 87.50 cm and 41.58 cm 2, tended to
be higher than the corresponding values in the DLPM pig was 79.67; 63.13; 57.28 kg, 84.67
cm and 39.59 cm2, respectively.
The dressing percentage, carcass percentage between the two groups of crossbred pigs
DLPM and PLDM were similar, respectively 78.76 and 79.27%; 71.99 and 71.92%, and


14

there was no statistically significant difference (P>0.05). The backfat thickness at position
P2 of these two crossbred pig groups were similar: 9.30 mm in PLDM pigs and 9.60 mm in
DLPM pigs (P>0.05). The results showed, backfat thickness in this study is lower than some
research results of some hybrid pigs with different VCN-MS15 breed.
The loin area in the middle of the 10-11 th rib of the two pig types DLPM and PLDM
was similar, ranging from 39.59 - 41.58 cm2. The lean percentages in the both DLPM and
PLDM pigs were quite high at 58.6% compared to 59.29% and similar (P>0.05). The lean
percentage in the two crossbred pig groups in this study was higher than those in previously
studied crossbred pigs with 1/2 and 1/4 of the VCN-MS15 breeds.
3.2.4. Meat quality
3.2.4.1. Technical quality measurements
The results on technical quality measurements of two crossbred pig groups showed in
Table 3.6.
Table 3.6.Technical quality measurements of DLPM and PLDM pig meats (Mean ± SE)
Item

DLPM
(
n = 6)

PLDM
(
n = 6)

P

6.22  0.09

6.16  0.07

>0.05

5.51  0.07

5.65  0.09

>0.05

5.44  0.03

5.58  0.07

>0.05

48.56  1.31

49.88  1.86

>0.05

3.97  0.29

4.61  0.24

>0.05

4.99  0.46

5.29  0.33

>0.05

52.27  1.51

52.25  1.74

>0.05

4.87  0.31

4.70  0.16

>0.05

5.93  0.74

5.54  0.58

>0.05

3.38  1.10

3.37  1.13

>0.05

4.32  1.62

5.00  1.80

>0.05

pH
pH45 (45’)
pH24 (24hr )
pH48 (48 hr)
Color
*

L 24 (bright at 24 hrs.)
*

a 24 (red at 24 hrs.)
*

b 24 (yellow at 24 hrs.)
*

L 48 (bright at 48 hrs.)
*

a 48 (red at 48 hrs.)
*

b 48 (yellow at 48 hrs.)
Drip loss (%)
24 hrs. after slaughter
48 hrs. after slaughter
Cooking loss (%)

15

29.25  0.47

27.87  0.47

>0.05

29.88  0.50

28.48  0.45

>0.05

40.41  5.94

51.01  7.26

>0.05

38.95  5.73

48.22  5.79

>0.05

24 hrs. after slaughter
48 hrs. after slaughter

Shear force value (N)
At 24 hrs. after slaughter
At 48 hrs. after slaughter

- pH value
The results in Table 3.6 showed that at 45 minutes after slaughter, pH values in the
loins of DLPM and PLDM pigs were 6.22 and 6.16 (P> 0.05), respectively. The value of
pH24 and pH48 after slaughter between the crossbred pig groups studied had no statistically
significant difference (P> 0.05) and ranged from 5.44 to 5.58. The pH 45 and pH24 values of
the DLPM and PLDM pigs in this study were within the normal meat classification limits
(Warriss, 2000).
- Meat color
Regarding meat color, the study results showed L* (light color), a* (red), b* (yellow)
values of the loin muscle at 24 hours after slaughter in the two crossbred pig groups of
DLPM and PLDM were 48.56; 3.97; 4.99 and 49.88; 4.61; 5.29 (P>0.05), respectively. The
L*, a*, b* values at 48 hours after slaughter were 52.27; 4.87; 5.93 and 52.25; 4.70; 5.54
(P>0.05), respectively. According to the color-based grading method (L* value) of Warner et
al (1997), the meat of the two crossbred pig groups in this study is normal.
- Drip loss
Drip loss after 24 and 48 hours of slaughter in DLPM and PLDM pigs were 3.38%;
4.32% and 3.37%; 5.00% (P>0.05), respectively. According to the meat quality
classification based on the rate of preservation dehydration (Honikel, 1998), the meat of two
crossbred pig groups of DLPM and PLDM is of good quality because there is a rate of water
loss after 24 hours in the range of 2 - 5%.
- Cooking loss
The percentages of cooking loss of meat after 24 and 48 hours of slaughter in the
DLPM and PLDM pigs were similar, at 29.25%; 27.87% (P>0.05) and 29.88%; 28.48%
(P>0.05), respectively.
- Tenderness
The tenderness is shown by the shear force of meat, which is an indicator that is very

concerned by consumers. The results of the measurement of the shear force in the eye loin
muscle 24 hours after slaughter in the DLPM and PLDM pigs were 40.41 N and 51.01 N
(P>0.05), respectively, at 48 hours after slaughter 38.95 N and 48.22 N (P>0.05).


16

3.2.4.2. Chemical composition of meat
The results on chemical composition of eye loin muscle in two pork types were
presented in Table 3.7.
Table 3.7. Chemical composition of loin muscle of DLPM and PLDM pigs (Mean ± SE)
Item

DLPM
(n = 6)
24.26  0.47

PLDM
(n = 6)
23.90  0.13

>0.05

20.74  0.12

21.04  0.15

>0.05

1.97  0.48

1.66  0.21

>0.05

1.16  0.02

1.16  0.02

>0.05

P

Dry matter (%)
Crude protein (% as meat)
Crude fat (% as meat)
Total ash (% as meat)

The content of dry matter, crude protein and total ash of the loins between the two pig
types DLPM and PLDM were similar, there was no statistically significant difference
(P>0.05) and were in average limit of pigs. The content of crude fat in the loin muscle
reflects the amount of fat present in the lean meat. The contents of crude fat in the loin
muscle of the DLPM and PLDM pigs were 1.97% and 1.66% (P>0.05), respectively. The
results of the chemical composition of the meat in this study are of guaranteed nutritional
quality. Crude fat content of the DLPM pig tended to be higher than that of the PLDM pigs.
3.2.4.3. Fatty acid composition

The results of fatty acid composition of loin muscle of two pig types DLPM and
PLDM were indicated in Table 3.8.
Table 3.8. Fatty acid composition in loin muscles (% as total fatty acid) of DLPM and

PLDM pigs (Mean ± SE)
Item

DLPM
(
n = 6)

PLDM
(
n = 6)

P


17

0.63  0.10

0.63  0.12

2.29  0.49

2.04  0.42

3.87  0.15

3.44  0.24

24.52  0.99

28.80  0.46

3.36  0.70

5.92  0.80

14.57  0.81

10.26  0.57

38.26  1.52

34.65  0.85

10.08  0.42

11.96  0.57

0.46  0.03

0.36  0.04

0.87  0.05

0.81  0.04

0.48  0.03

0.48  0.04

0.61  0.03

0.65  0.04

45.88  1.22

45.17  0.97

54.12  1.22

54.83  0.97

42.51 1.39

41.38  0.77

11.61  0.44

13.45  0.51

1.18  0.06

1.21  0.05

0.25  0.01

0.29  0.02

Caparic (C10:0)
Lauric (C12:0)

Myristic (C14:0)
Palmitic (C16:0)
Palmitoleic (C16:1)
Stearic (C18:0)
Oleic (C18:1)
Linoleic (C18:2)
Linolenic (C18:3)
Eicosenoic (C20:1)
Eicosadiennoic (C20:2)
Arachidonic (C20:4)
Saturated fatty acid (SFA)
Unsaturated fatty acid (UFA)
Mono-UFA (MUFA)
Poly-UFA(PUFA)
UFA/SFA ratio
PUFA/SFA ratio

>0.05
>0.05
>0.05
<0.01
<0.05
<0.01
>0.05
<0.05
>0.05
>0.05
>0.05
>0.05
>0.05

>0.05
>0.05
<0.05
>0.05
<0.05

The results in Table 3.8 show that the main fatty acids in the loin muscle in the two
studied pig types are C16:0, C18:0, C18:1 and C18:2. In PLDM pigs, the percentage of fatty
acids C16:0 (28.80%), C16:1 (5.92%) and C18:2 (11.96%) was significantly higher than the
ratio of fatty acids C16:0 (24.52%) (P<0.01), C16:1 (3.36%) and C18:2 (10.08%) (P<0.05)
in DLPM pigs; The ratio of fatty acids C18:0 (10.26%) in PLDM pigs was lower than C18:0
(14.57%) in DLPM pigs (P<0.01).
The SFA percentage in the loin muscle in the two pig types in this study ranged from
45.17 to 45.88%, there was no difference (P>0.05); The percentage of MUFA in the loin


18

muscle in two pig types in this study ranged from 41.38 to 42.51% (P>0.05); The PUFA
percentage in PLDM pigs was 13.45%, significantly higher (P<0.01) compared to 11.61%
in DLPM pigs.
The ratios of UFA/SFA in the loin muscle in the 2 studied pig types were 1.18 and
1.21, respectively, and there was no statistically significant difference (P>0.05); The ratio of
PUFA/SFA in the loin muscle in the PLDM pig was 0.29, statistically higher than that in the
DLPM pig which was 0.25 (P<0.05).
3.3. GROWTH PERFORMANCE, MEAT YIELD AND QUALITY OF PIC280LDM
AND PIC399LDM CROSSBRED PIGS
3.3.1. Live weight and daily weight gain
The results on live weight and average daily gain of two pig types studied were
presented in Table 3.9.

Table 3.9. Live weight (LW) and average daily gain (ADG) of PIC280LDM and
PIC399LDM pigs during the experimental period (Mean ± SE)
PIC280LDM
PIC399LDM
Item
P
(n = 18)
(n = 18)
Initial BW, 60 days old (kg/head)
20.33 ± 0.78
20.52 ± 0.56
>0.05
LW at 90 days old (kg/head)
40.61 ± 0.91
41.88 ± 0.65
>0.05
LW at 120 days old (kg/head)
64.38 ± 1.03
66.61 ± 0.95
>0.05
Final BW at 150 days old (kg/head)
90.11 ± 1.29
95.00 ± 1.50
<0.05
ADG, 60-90 days old (g)
675.93 ± 12.65
712.00 ± 14.49
>0.05
ADG, 90-120 days old (g)
792.59 ± 4.40

824.08 ± 16.78
>0.05
ADG,120-150 days old (g)
857.41 ± 16.78
946.29 ± 26.83
<0.01
ADG, whole period (g)
775.31 ± 8.51
827.50 ± 15.80
<0.01
Data in Table 3.9 shows that, the live weight of pigs at the beginning of the experiment
in two pig types PIC280LDM and PIC399LDM at 60 days old are equivalent to 20.33 and
20.52 kg (P>0.05). The live weight at the end of the 150-day-old experiment of the
PIC399LDM pig was 95.00 kg, higher than that of PIC280LDM pig which was 90.11 kg
(P<0.05).
The overall ADG of 775.31 g of the PIC280LDM pig was quite high, but lower than
the result of 827.50 g of the PIC399LDM pig (P<0.01).
3.3.2. Daily feed intake and feed conversion ratio
The results on daily feed intake (DFI) and feed conversion ratio (FCR) of the crossbred
PIC280LDM and PIC399LDM pigs during the experiment were presented in Table 3.10.


19

Table 3.10. Daily feed intake (DFI) and feed conversion ratio (FCR) of PIC280LDM
and PIC399LDM pigs during the experimental period (Mean ± SE)
PIC280LDM
PIC399LDM
Item
P

(n = 18)
(n = 18)
DFI at 1st feeding month (kg/head)
1.37 ± 0.02
1.47 ± 0.01
<0.01
DFI at 2nd feeding month (kg/head)
1.99 ± 0.02
2.07 ± 0.03
>0.05
rd
DFI at 3 feeding month (kg/head)
2.63 ± 0.05
2.80 ± 0.06
<0.05
Overall DFI (kg/head)
2.00 ± 0.02
2.11 ± 0.03
<0.01
FCR at 1st feeding month
2.08 ± 0.03
2.07 ± 0.03
>0.05
nd
FCR at 2 feeding month
2.51 ± 0.03
2.52 ± 0.02
>0.05
FCR at 3rd feeding month
3.06 ± 0.02

2.98 ± 0.04
>0.05
Average FCR
2.56 ± 0.02
2.53 ± 0.02
>0.05
The average feed intake during the whole feeding period of PIC280LDM pig was 2.00
kg/head/day which was lower (P<0.01) compared to 2.11 kg/head/day in PIC399LDM pig.
This result shows that the PIC399LDM pig has a higher ability to receive feed than the
PIC280LDM pig. The mean FCRs in both pig types were 2.56 and 2.53, respectively, and
there was no statistically significant difference (P>0.05).
3.3.3. Carcass characteristics
The results on carcass traits of two pig types were presented in 3.11.
Table 3.11. Carcass traits of PIC280LDM and PIC399LDM pigs(Mean ± SE)
PIC280LDM
PIC399LDM
Item
P
(n = 6)
(n = 6)
Live weight at slaughter (kg)
94.00 ± 2.35
99.33 ± 2.84
>0.05
Dressing weight (kg)
74.07 ± 2.21
78.47 ± 2.65
>0.05
Dressing percentage (%)
78.76 ± 0.69

78.95 ± 0.64
>0.05
Carcass weight (kg)
67.32 ± 1.92
71.30 ± 1.62
>0.05
Carcass percentage (%)
71.59 ± 0.39
71.84 ± 0.50
>0.05
Carcass length (cm)
92.67 ± 1.48
95.33 ± 1.17
>0.05
Backfat thickness at P2 (mm)
9.40 ± 0.07
10.42 ± 0.07
>0.05
2
Loin muscle area (cm )
55.38 ± 1.14
58.73 ± 0.89
>0.05
Lean/carcass ratio (%)
59.08 ± 0.72
60.26 ± 0.74
>0.05
The data in Table 3.11 shows that the dressing percentage, carcass percentage between
PIC280LDM and PIC399LDM pigs did not differ, 78.76%; 71.59% and 78.95%; 71.84%
(P>0.05), respectively. Carcass lengths of the two pig types PIC280LDM and PIC399LDM

were 92.67 and 95.33 cm, respectively (P>0.05).
The results of the study showed that backfat thickness at P 2 of the PIC280LDM and
PIC399LDM pigs at slaughter weights 94.80 kg and 99.33 kg were 9.40 and 10.42 mm
(P>0.05), respectively. This result is lower than the hybrid pig combinations with different
VCN-MS15 breed ratios previously studied.
The loin muscle areas of the PIC280LDM and PIC399LDM pigs were 55.38 and 58.73
2
cm (P>0.05), respectively. The results of our study are higher than that of crossbred pigs
with 1/4 VCN-MS15 breed in the study of Phung Thang Long et al (2015).


20

Lean percentage is an important indicator of carcass quality, it is strongly correlated
with eye area. Therefore, the lean percentage of the two groups was quite high at 59.08%
and 60.26% (P>0.05), respectively.
3.3.4. Meat quality
3.3.4.1. Technical quality measurements
The results on technical measurements of meats were presented in Table 3.12.
Table 3.12.Technical measurements of PIC280LDM and PIC399LDM pork (Mean ± SE)
PIC280LDM
PIC399 LDM
Item
(
(
P
n = 6)
n = 6)
pH
pH45 (45’)

6.28 ± 0.09
5.99 ± 0.12
>0.05
pH24 (24 hr.)
5.62 ± 0.09
5.54 ± 0.02
>0.05
pH48 (48 hr.)
5.59 ± 0.05
5.50 ± 0.03
>0.05
Color
L*24 (bright at 24 hr.)
48.50 ± 1.45
47.81 ± 0.55
>0.05
*
a 24 (red at 24 hr.)
4.50 ± 0.38
3.71 ± 0.14
>0.05
b*24 (yellow at 24 hr.)
4.63 ± 0.35
4.45 ± 0.38
>0.05
*
L 48 (bright at 48 hr.)
51.43 ± 1.03
51.87 ± 1.10
>0.05

a*48 (red at 48 hr.)
4.82 ± 0.46
4.76 ± 0.37
>0.05
*
b 48 (yellow at 48 hr.)
4.91 ± 0.48
5.88 ± 0.75
>0.05
Drip loss (%)
After 24 hr. slaughter
After 48 hr. slaughter
Cooking loss (%)
After 24 hr. slaughter
After 48 hr. slaughter
Shear force value (N)
At 24 hr.
At 48 hr.

2.45 ± 0.25
3.54 ± 0.42

3.44 ± 0.59
4.59 ± 0.55

>0.05
>0.05

27.90 ± 0.50
28.87 ± 0.77

29.43 ± 0.75
30.41 ± 0.54

>0.05
>0.05

41.64 ± 1.57
43.34 ± 2.13

47.16 ± 3.82
50.30 ± 2.02

>0.05
<0.05

- pH
The pH value is one of the important criteria to evaluate technical quality of the meat.
The results in Table 3.12 showed that after slaughter 45 minutes pH 45 in PIC280LDM and
PIC399LDM pork were 6.28 and 5.99, respectively (P>0.05). The value of pH 24 and pH48
between the two groups varied from 5.50 to 5.62 (P>0.05). The pH 45 and pH24 values in this
study are within the normal meat classification limits (Warriss, 2000).
- Color
Meat color (L*, a* and b*) are sensory indicators used to evaluate and classify meat
quality. L* 24, a* 24 and b* 24 values after slaughter of the two pig meat types
PIC280LDM and PIC399LDM were 48.50; 4.50; 4.63 and 47.81; 3.71; 4.45 (P>0.05),
respectively. The L* 48, a* 48 and b* 48 values of the two pig meat types were 51.43; 4.82;
4.45 and 51.87; 4.76; 5.88 (P>0.05), respectively. According to the color-based grading
method (L* value) of Warner et al (1997), the meat quality of the two pig meat in this study
is normal.

21

- Drip loss
Drip loss after 24 and 48 hours of slaughter in crossbred PIC280LDM and
PIC399LDM pigs were 2.45 and 3.44% (P> 0.05), 3.54 and 4.59%, respectively (P> 0.05).
The storage water loss at 48 hours of storage in the two pig meats studied tended to increase
gradually compared to after 24 hours of storage. According to the meat quality classification
based on the storage water loss from Honikel (1998), the meat of the PIC280LDM and
PIC399LDM pigs are of guaranteed quality because of the 24-hour storage range of 2 - 5%.
- Cooking loss
Cooking loss after 24 and 48 hours of slaughter of the PIC280LDM and PIC399LDM
pig meats were 27.90%; 29.43% (P>0.05) and 28.87%; 30.41% (P> 0.05), respectively.
- Shear force value
The results of shear force value of PIC280LDM pig meat after 24-hours slaughter
tended to be lower than that of the PIC399LDM pig meat (41.64 vs 47.16 N), but not
significantly different (P>0.05). However, the value of shear force of the PIC399LDM pig
meat at 48 hours after slaughter was higher than that of the PIC280LDM meat (50.30 vs
43.34 N) P<0.05. This may be due to the higher proportion of Duroc breed in the
PIC280LDM pigs than that in the PIC399LDM pig.
3.3.4.2. Chemical composition of meat
The results on chemical composition of the longissimus dorsi muscle of 2 crossbred
pig genotypes were presented in Table 3.13.
Table 3.13.Chemical composition of longissimus dorsi muscle of PIC280LDM and
PIC399LDM pigs (Mean ± SE)
PIC280LDM
PIC399LDM
P
(n = 6)

(n = 6)
Dry matter (%)
24.31 ± 0.40
24.47 ± 0.24
>0.05
Crude protein (% as meat)
21.43 ± 0.23
22.26 ± 0.34
>0.05
Crude fat (% as meat)
2.77 ± 0.37
1.81 ± 0.04
<0.05
Total ash (% as meat)
1.18 ± 0.03
1.17 ± 0.02
>0.05
The contents of dry matter, crude protein and total ash of the loins between the two
crossbred PIC280LDM and PIC399LDM pigs were 24.31%; 21.43%; 1.18% and 24.47%;
22.26%; 1.17% (P> 0.05), respectively. Le Dinh Phung et al (2015) reported that, the
contents of dry matter, crude protein and total ash of two crossbred PIC280 × (Landrace ×
Yorkshire) and PIC399 × (Landrace × Yorkshire) pigs were 25.28%; 21.71%; 2.16% and
25.28%; 23.12%; 2.10%, respectively. The content of crude fat in the loin muscle of the
PIC280LDM pig at a slaughter weight of 94.00 kg reached 2.77%, within the ideal level and
was statistically significantly higher (P<0.05) compared to the content 1.81% at 99.33 kg
slaughter weight of the PIC399LDM pig.
3.3.4.3. Fatty acid composition of the loin muscle
The results of fatty acid composition of the longissimus dorsi muscles of two
crossbred pig genotypes presented in Table 3.14.
Item

22

Table 3.14. Fatty acid composition of the loin muscle (% as total fatty acid) of the
PIC280LDM and PIC399LDM pigs (Mean ± SE)
PIC280LDM
(n = 6)

PIC399LDM
(n = 6)

P

Myristic (C14:0)

2.14 ± 0.21

2.19 ± 0.20

>0.05

Palmitic (C16:0)

25.77 ± 0.32

25.51 ± 0.45

>0.05

Palmitoleic (C16:1)

2.94 ± 0.28

3.42 ± 0.23

>0.05

Stearic (C18:0)

13.59 ± 0.19

13.42 ± 0.18

>0.05

Oleic (C18:1)

44.06 ± 0.52

43.02 ± 0.45

>0.05

Linoleic (C18:2)

9.34 ± 0.17

10.40 ± 0.18

<0.01

Linolenic (C18:3)

0.63 ± 0.06

0.33 ± 0.90

<0.05

Eicosenoic (C20:l)

0.88 ± 0.07

0.74 ± 0.10

>0.05

Arachidonic (C20:4)

0.64 ± 0.17

0.96 ± 0.41

>0.05

Saturated fatty acids (SFA)

41.51 ± 0.44

41.13 ± 0.37

>0.05

Unsaturated fatty acids (UFA)

58.49 ± 0.44

58.87 ± 0.37

>0.05

Mono-UFA (MUFA)

47.88 ± 0.38

47.18 ± 0.45

>0.05

Poly-UFA (PUFA)

10,61 ± 0,27

11,69 ± 0,29

<0.05

UFA/SFA ratio

1.41 ± 0.03

1.43 ± 0.02

>0.05

Item

0.26  0.01
0.28  0.01
< 0.05
PUFA/SFA ratio
The results of fatty acid composition in the longissimus dorsi muscle of the
PIC280LDM and PIC399LDM pigs showed that the main fatty acids in the meat were
C16:0, C18:0, C18:1 and C18:2. On the other hand, except for the C18:2, fatty acid ratio in
the PIC399LDM crossbred pig which was 10.40%, which was higher than the 9.34% of the
PIC280LDM pigs (P<0.05). The C18:3 fatty acid concentration in the PIC280LDM pigs
was 0.63%, higher than that of 0.33% in the PIC399LDM pigs (P<0.05). The percentage of
remaining fatty acids between two crossbred pigs genotypes was similar (P>0.05).
The SFA concentration in the longissimus dorsi muscle of the two PIC280LDM and
PIC399LDM crossbred pigs were 41.51% and 41.13%, respectively, and there was no
statistically significant difference (P>0.05). The concentration of MUFA in the loin muscle
in the two researched crossbred pig genotypes was no difference (P>0.05). The PUFA
concentration in the crossbred PIC399LDM pig was 11.70%, significantly higher than 10.60
% in the PIC280LDM pig (P<0.05). The concentrations of UFA in the loin muscle in the
two PIC280LDM and PIC399LDM crossbred pig genotypes were 58.49 and 58.87
(P>0.05), respectively.
The PUFA/SFA ratio in the loin muscle in the PIC399LDM pig was 0.28, higher than
that in the PIC280LDM pig, which was 0.26 and the difference was statistically significant
(P<0.05). As recommended by Ulbrich and Southgate (1991), the best PUFA/SFA ratio is

0.4 (cited by Kasprzyk et al., 2015). Thus, the PUFA/SFA ratio in longissimus dorsi muscle


23

of two crossbred pig genotypes are lower than the above recommendations, so it is
necessary to pay attention to diet during fattening period.
Chapter 4
CONCLUSIONS AND RECOMMENDATION
4.1. CONCLUSIONS
- Landrace × (Pietrain × VCN-MS15) and Landrace × (Duroc × VCN-MS15)
crossbred sows fed with commercial feed, in opened housing in Thua Thien Hue province
had early first estrus age (146.50 - 155.60 days ) and the mated age (186.10 - 187.00 days).
Landrace × (Pietrain × VCN-MS15) sows were mated from Duroc boars and Landrace ×
(Duroc × VCN-MS15) sows were inseminated from Pietrain boars for high reproductive
performance: at parities 3-4, Landrace × (Pietrain × VCN-MS15) and Landrace × (Duroc ×
VCN-MS15) sows had 13.88 and 13.50 offspring/litter; the number of alive piglets/litter
reached 12.94 and 12.75 heads, the number of piglets weaned at 30 days of age/litter
reached 11.87 and 11.68 heads. The average weight of newborn piglets reached 1.26 and
1.26 kg/head; The weight of piglets weaned at 30 days of age reached 7.10 and 6.85 kg /
head, respectively.
- Duroc × [Landrace × (Pietrain × VCN-MS15)] and Pietrain × [Landrace × (Duroc ×
VCN-MS15)] crossbred pigs were raised by commercial feed in the open housing in Thua
Thien Hue from 60 - 160 days old had the fast daily weight gain (651.30 - 722.50 g/day),
low feed conversion ratio (2.58 - 2.60) and high pork yield and quality: The killing out
percentage was 78.76-79.27%, dressing percentage was 71.92 - 71.99%, the lean meat
percentage was 58.60 - 59.29% and low back fat thickness at P2 position (9.3 - 9.6 mm).
The meat quality indicators including pH values, color, drip loss, cooking loss, shear force
value, chemical composition and fatty acid composition in Longissimus dorsi muscle of the
two hybrid combinations was similar and within the limits of accepted meat quality

- PIC280 × [Landrace × (Duroc × VCN-MS15)] and PIC399 × [Landrace × (Duroc ×
VCN-MS15)] crossbred pigs raised by commercial feed in the opened housing from 60 to
150 days old had fast daily weight gain ( 775.31 - 827.50 g/day), low feed conversion ratio
(2.53 - 2.56). Pork productivity was high: specifically the killing out percentage was 78.76 78.95%, the dressing percentage was 71.59 - 71.84%, lean meat percentage reached 59.08 60.26% and thick back fat at P 2 was the low (9.40 - 10.42 mm). The pork quality indicators
including pH values, color, drip loss, cooking loss, shear force value, chemical composition
and fatty acid composition of Longissimus dorsi muscle in the two crossbred pig genotypes
were similar and within the limits of accepted meat quality. However, PIC280 × [Landrace
× (Duroc × VCN-MS15)] crossbred pigs had a higher percentage of intramascular fat in the
logissimus dorsi muscle of 2.77% compared with 1.81% in PIC399 × [Landrace × (Duroc ×
VCN-MS15)] crossbred pigs.
4.2. RECOMMENDATION
- Landrace × (Pietrain × VCN-MS15) and Landrace × (Duroc × VCN-MS15)
crossbred sows had high reproductive performance, and suitable for production conditions