MINISTRY OF EDUCATION
AND TRAINNING
MINISTRY OF AGRICULTURE
AND RURAL DEVELOPMENT
NATIONAL INSTITUTE OF ANIMAL SCIENCES
HONG SON TRINH
PERFORMANCE AND ESTIMATED BREEDING VALUE
OF VCN03 SIRE LINE
MAJOR: ANIMAL GENETICS AND BREEDING
CODE NUMBER: 62.62.01.08
SUMMARY OF PhD THESIS
HANOI, 2014
PhD thesis was conducted at: National institute of animal sciences
Supervisor:
Dr. Que Coi Nguyen
Ass. Prof. Dr. Van Chinh Dinh
Reviewer 1: ………………………………………………………….
………………………………………………………………………..
Reviewer 2: …………………………………………………………..
…………………………………………………………………………
Reviewer 3: …………………………………………………………...
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The PhD theses will be defended at PhD thesis examination Committee of
National Institute of Animal Sciences on
.… h … day …. Month …. , 2014.
This PhD thesis can be found in:
- National Library of Vietnam
- Library of National Institute of Animal Sciences
LIST OF PUBLICATIONS RELATED TO THE PHD THESIS
1. Hong Son Trinh, Que Coi Nguyen and Van Chinh Dinh (2013). Semen characteristics, heritability and
factors affecting semen quality of boars of VCN03 sire line. Journal of Science and Development, Vol.
46: 6-12.
2. Hong Son Trinh, Que Coi Nguyen and Van Chinh Dinh (2013). Growth Performance, Carcass
Characteristics and Meat Quality of Boars of VCN03 sire line. Journal of Science and Development,
Vol. 11: 965-971.
3. Hong Son Trinh, Que Coi Nguyen and Van Chinh Dinh (2014). Heritability and estimated breeding value
for some reproductive traits of sows of VCN03 sire line. Journal of Science and Development, Vol. 10:
9-18.
1
Chapter I
INTRODUCTION
1.1.
Rational
Two methods used for improvement of productivity and product quality in pig industry are selection,
pure breeding and crossbreeding. VCN03 sire line (L19 - White Duroc) plays a key role in the breeding
program of the PIC and is used to produce parental pig in breeding systems of Vietnamese PIC, and
meanwhile it plays an important role in promoting lean pig programs in Vietnam. However, so far some
production traits and meat quality of VCN03 sire line have not been yet properly and systematically studied
to identify genetic parameters and estimate breeding values.
For a higher efficiency of VCN03 sire line selection in particular and contributing to enhancement of
productivity, quality, and efficiency of pig production in PIC pig breeding systems at Vietnam in general, it
is necessary to investigate “performance and estimated breeding value of VCN03 sire line” at Tamdiep pig
research and development station.
1.2.
1.3.
Objectives of the study
Evaluation of the reproductive performance of VCN03 dam line; quantity and quality of semen
VCN03 sire line; growth potential, performance and meat potential of the VCN03 sire line
Determination of heritability and estimated breeding value of some reproductive traits of VCN03 dam
line; and growth and meat potential traits of VCN03 sire line.
The novelty of thesis
It was the first time in Vietnam, one systematic and scientific work on reproductive performance of
VCN03 dam line; quantity and quality of boar semen of VCN03 sire line; growth, yield and quality of meat
of VCN03 sire line was published.
It also was the first time in Vietnam, heritability and estimated breeding value of reproductive traits of
sows of VCN03 dam line, growth and the meat potential traits of boars of VCN03 sire line were determined.
Estimated breeding value of some production traits was applied in a selection program to improve
productivity and quality of VCN03 sire line.
1.4.
Scientific and practical meaning of the thesis
The thesis provided the additional technical information on productivity, heritability and estimated
breeding value of reproductive traits of sows, growth and meat potential traits of VCN03 sire line.
Estimated breeding value of some reproductive and production traits was applied in a selection
program to improve productivity and quality of VCN03 sire line.
One group of sows with high reproductive performance of VCN03 dam line and one group of boars
with high growth and meat potential of VCN03 sire line have been selected. VCN03 sire line with high
productivity and quality have been created to produce parental sows and to contribute to improving
economic efficiency in the pig industry.
Chapter II
LITERATURE REVIEW
Selection of high-yield lines in pigs and crossbreeding programs to find out the crosses complexes,
which give more newborn piglet/litter, higher lean meat percentage, lower feed consumption and lower back
fat thickness, were successful in developed countries with advanced animal production levels such as
America, Germany, Canada, Britain, the Netherlands, Denmark and Australia (Hermesch et al., 1995;
Alfonso et al., 1997).
2
On Yorkshire and Landrace, estimated heritability for newborn piglet/litter and weight at 21 day
old/litter traits have been reported from 0.03 to 0.20 (Hermesch et al., 2000; Hanenberg et al., 2001; Chen et
al., 2003; Hamann et al., 2004; Arango et al., 2005; Rho et al., 2006; Imboonta et al., 2007). For the average
body weight gain/day, reported heritability was significantly different among studies and ranged from 0.13 to
0.42 (Chen et al., 2003; van Wijk et al., 2005; Roh et al., 2006; Imboonta et al., 2007).
Similarly, heritability of back fat thickness trait was reported from 0.50 to 0.71 (Hicks et al., 1998;
Chen et al., 2003; Rho et al., 2006; Imboonta and et al., 2007). The reason for significant difference among
studies was due to the different populations of gene frequency, differences in data sources as well as
different calculated methods.
Genetic progress for newborn piglet/litter trait in the United States was increased from 0.36 to 0.63
piglets (Mabry et al., 2001; Holl and Robinson, 2003; Boyette et al., 2005).
Pig productivity was reported to be affected by breed, halothane genotype factors (Phung Thi Van et
al., 2001; Phan Xuan Hao, 2002; Phan Van Hung and Dang Vu Binh, 2008; Do Duc Luc et al., 2008 ; Phan
Xuan Hao and Nguyen Van Chi, 2010; Doan Van Viet and Dang Vu Binh, 2010; Ha Xuan Bo et al., 2013a).
BLUP method had been applied in Vietnam to determine the estimated breeding value in pigs for a
while in Vietnam (Ta Thi Bich Duyen and Nguyen Van Duc, 2001; Nguyen Ngoc Tuan and Tran Thi Dan,
2001; Ta Thi Bich Duyen 2003; Tran Van Chinh, 2004; Nguyen Thi Vien, 2005; Nguyen Van Hung and
Trinh Cong Thanh, 2006; Pham Thi Kim Dung and Ta Thi Bich Duyen, 2009; Ta Thi Bich Duyen et al.,
2009). PigBLUP was also used to assess the genetic value through herds (Willi Funchs, 1991; Tony Henzell,
1993; Tom Long, 1995; 5:20 PigBLUP version of user's manual, 2006).
Selective index based on phenotypic values of production traits of pig was established (Cleveland et
al., 1983; McPhee, 1981; Ellis et al., 1988; Tran The Thong, Le Thanh Hai, 1982 ; Dang Vu Binh, 1992; Le
Thanh Hai et al., 1998; Nguyen Hong Hanh, Nguyen Que Coi, 2000; Che Radiology et al., 2001; Vu Dinh
Ton et al, 2004).
However, so far the productivity of VCN03 line has not been yet comprehensively and systematically
studied and evaluated. The determination of heritability and estimated breeding value of reproductive traits
of sows, growth and the meat potential traits of boars and application of estimated breeding value of some
production traits in selection to improve productivity and quality of VCN03 sire line have not been studied in
Vietnam.
Chapter III
PRODUCTIVITY OF VCN03 BOAR LINE
3.1.
Reproductive potential of VCN03 dam line
3.1.1.
Introduction
L19 pig line (White Duroc) or VCN03 (new name) has been received and reared by Thuy Phuong Pig
Research Center since 2001. However, over a period of exploitation and utilization, breeding pigs has not
been fully examined their reproductive potential. It is essential to create a basis for selection, breeding
improvement in subsequent generations, an assessment of factors affecting productivity and productivity of
VCN03 line is very critical. The purpose of this study was to evaluate the production potential and the
influence of some factors on the production potential of VCN03 line.
3.1.2.
Materials and methods
3.1.2.1. Subjects of study
-
VCN03 line: 362 pigs with 1129 litters.
3.1.2.2. Methods
3
- The study was conducted at Tamdiep pig research and development station belonging to Thuy
Phuong Pig Research Centre - National Institute of Animal Sciences. Data on reproductive performance of
VCN03 dam line were collected from data base stored in Computers using PPM management software from
2002 to 6/2010 and collected directly in the station from 7/2010 to 4/2013.
- Piglet number was determined by counting at the time of delivery, weaning, and after weaning. Body
weight was determined by a scale at the time of delivery, weaning.
- The data were analyzed using SAS 9.1 software (2002). The statistical parameters were: sample size
(n), Mean, maximum value (Max), minimum value (Min). GLM procedure was used to calculate least square
mean (LSM), standard error (SE) and to assess impacts of some factors on studied parameters. The
mathematical model for a statistical analysis was as follow:
Yijk = μ + THi + Lj + Nk + εijk
Where: Yijk: reproductive performance; μ: the population mean; TH: effect of the ith generation (i = 1,
2, 3, 4); Lj: effect of jth parity (j = 1, 2, 3, 4, 5, 6, 7); Nk : effect of kth year (k = 2002, 2003 ... .., 2013); εijk:
random error.
Pair comparison among LSM values was done using Turkey comparisons.
3.1.3.
Results and Discussion
3.1.3.1. Factors affecting the reproductive performance of sows of VCN03 line
Reproductive performance of VCN03 dam line was not affected by generations (P> 0.05). Litters
affected alive newborn/litter and weaning weight/piglet (P <0.01). Years affected weaned number/litter,
weaned weight/litter, newborn weight, weaning weight/piglet and weaning weight/litter (P <0.001). These
results were consistent with findings of some authors such as Tran Thi Minh Hoang et al. (2006; 2008b);
Dang Vu Binh et al. (2008); Pham Thi Kim Dung and Tran Thi Minh Hoang (2009); Doan Van Soan and
Dang Vu Binh (2010).
3.1.3.2. Reproductive performance of sows of VCN03 line
Sows of VCN03 line had a low number of alive newborn number/litter (8.85 piglets/litter), a high
newborn weight (1.56 kg/piglet) and high growth potential (weaning weight: 6.72 kg/piglet). Imboonta et al.
(2007) reported that alive newborn number/litter of Landrace pigs in Thailand was 10.03 piglets.
According to Nguyen Huu Tinh (2009), newborn number/litter, weaned weight/ litter at 21 days of age
of Landrace and Yorshire sows in the southern provinces in the period from 1995 to 2005 were 9.60 and
9.57litter, and 58.79 and 57.26 kg/litter; respectively. This author also reported that newborn number/litter,
weaned weight/ litter at 21 days of age of Landrace and Yorshire sows in the southern provinces in the
period from 2000 to 2007 were 9.70 and 9.80 piglets/litter, and 54.10 and 54.09 kg/litter, respectively.
Thus, sows from VCN03 line were from "sire line '', which were characterized by lower reproductive
performance compared to reproductive performance of sows from dam lines. Sows from dam lines, for
example: Meishan, had a higher reproductive performance. On average, number of newborn alive/litter of
Meishan was 14-16.
Reproductive performance of sows, which were born from mating between boars of sire line and
crossbred sows was also higher. Phan Van Hung and Dang Vu Binh (2008) reported that newborn number,
weaned number/litter of F1 hybrid sows (LxY), Du x F1(YxL), L19 x F1(LxY) and L19 x F1(YxL) were
10.00; 10.43; 10.27 and 10.61 piglets/litter; 9.60; 9.89; 9.72 and 10.00 piglets/litter, respectively. Doan Van
Soan and Dang Vu Binh (2010) reported that number of born alive and weaned number of F1 hybrid sows (L
x Y) with Duroc boars and L19 (or VCN03) were 11.26 and 11.44 piglets/litter, and 10.37 and 10.46
piglets/litter respectively. However, newborn weight/piglet was 1.49 and 1.47 kg/piglet, respectively.
4
3.1.3.3. Reproductive performance of sows of VCN03 line over generations
Newborn number/litter was decreased from one generation to another, being the highest in the first
generation and the lowest in the fourth generation. Newborn number /litter of the first generation was 9.29
piglets and decreased by 0.49 piglets/litter in the second generation. This decreased trend also occurred in the
thirst and the fourth generations at lower rate. The main reason for that was VCN03 sire line was only kept in
Thuy Phuong Pig research center in our country and has not been improved for a long time. To enhance
genetic value, stabilize performance and quality, Center has already imported a new genetic resource from
abroad since 2005.
Newborn weight/litter was the highest in the first generation, decreased in the next generation (2, 3
and 4). Newborn weight/litter of the first generation was higher due to higher newborn number/litter. In
contrast, weaned weight/litter was the lowest in the first generation. Weaned weight/litter increased in the
second and thirst generations then decreased in the fourth generation. Lower weaned weight/litter of the first
generation may be due to the inappropriate feeding of sows with piglets of VCN03 line. However, newborn
weight/litter and weaned weight/litter of sows of VCN03 line over generations were not significantly
different (P≥0.05).
Alive newborn weight/piglet over 4 generations was high, from 1.55 to 1.57 kg/piglet, and no
significant difference over generations was found. Weaned weight/piglet was negatively correlated with
weaned number/litter. In the first generation, while weaned number/litter was the highest, weaned weight
/piglet was the lowest. Weaned weight /piglet was the lowest in the first generation then increased in the next
generation and seemed to be stable later. Similar to alive newborn weight/litter, weaned weight/piglets over
generation was not statistically significantly different (P≥0.05).
Thus, alive newborn number/litter, weaned number/litter, and alive newborn weight/litter decreased
from the first generation to the fourth generation. Alive newborn weight/piglet was relatively stable over
generations. Weaned weight/litter slightly increased in the second generation and was relatively stable in the
thirst and fourth generations. For exotic pigs, after more than 10 years raising, fertility was in stability and
positive result.
3.1.3.4. Reproductive performance of sows of VCN03 line over parities
Newborn number/litter, weaned number/litter of sows of VCN03 line over parities was presented in
Table 4. The results showed that newborn number/litter was the lowest in the first parity, increased in the
second parity, was the highest in the thirst parity, decreased in the fourth parity, increased in the fifth and
sixth parities and decreased again in the other late parities. The variation in alive newborn number/litter and
weaned number/litter of sows of VCN03 line over parities was not similar with the report of Yen et al.
(1987).
Table 4: Newborn number/litter, weaned number/litter of sows of VCN03 line over parities
Parities
Newborn number/litter (piglet)
Weaned number/litter (piglet)
n
LSM
SE
n
LSM
SE
1
229
8,50a
0,16
218
7,89
0,14
2
204
8,78ab
0,17
194
8,00
0,14
3
185
b
9,19
0,17
176
8,35
0,14
4
151
8,61a
0,19
143
8,04
0,15
5
133
9,16b
0,20
125
8,21
0,17
6
100
9,23b
0,23
93
8,35
0,19
5
≥7
8,69ab
127
0,21
117
7,97
0,18
* Within column, LSM values bearing different superscripts differ (P<0, 05)
Newborn number/litter, weaned number/litter of sows of VCN03 line tended to increase from the first
parity to the thirst parity. However, alive newborn number/litter of the fourth parity was markedly reduced
compared to that of the thirst parity. The cause of this situation may be due to the biological cycle
characteristics of VCN03 line, it was different from other breeds. It was found out that culling rate of sows of
VCN03 line after the thirst parity was the highest (18.38% ). The high culling rate of sows may affect alive
newborn number/litter. However, at the fifth parity, newborn number/litter recovered and was the highest in
the sixth parity. The reason for the highest newborn number/litter in the sixth parity was that in this parity,
sows with a poor performance were culled. Culling rate from the first parity to sixth parity was 56.33%.
Similar to sows from other exotic breeds, newborn number/litter was remarkably reduced in the sixth parity.
Along with the breed factor, environmental factors affected reproductive performance including newborn
number/litter of sows.
Alive newborn weight/litter over parities varied in a similar trend of alive newborn number/litter.
Newborn weight/litter in the fourth parity was lower than that of other parities. It may be due to the fact that
number born alive/litter was low. However, no significant difference in alive newborn weight/litter, weaned
weight/litter over parities was found. This finding indicated that parity did not affect newborn weight/litter
and weaned weight/litter. It appeared that variation of weaned weight/piglet were greater than that of weaned
weight/litter. Weaned weight/litter was low in the first parity (6.46 to 6.88 kg/piglet), increased in the second
parity, then was stable in the thirst, fourth and fifth parities, significantly reduced in the sixth parity 6 and
increased again at seventh parity. Differences in weaned weight/piglet over parity were statistically
significant (P <0.05).
3.1.3.5. Reproductive performance of sows of VCN03 line over the years
Alive newborn number/litter and weaned number/litter of sows of VCN03 line over the years were
presented in Table 6.
Table 6: Alive newborn number/litter and weaned number/litter of sows of VCN03 line over the years
Alive newborn number/litter (piglets)
weaned number/litter (piglets)
Year
n
LSM
SE
n
LSM
SE
2002
123
8,55
0,28
116
7,70ac
0,23
abc
0,22
2003
109
8,60
0,25
93
7,87
2004
89
8,53
0,26
80
7,98abcd
0,22
2005
106
8,68
0,25
102
7,86ac
0,21
ac
0,20
2006
99
8,67
0,25
97
7,81
2007
119
9,16
0,22
112
8,32abd
0,18
2008
113
9,29
0,22
113
8,34abd
0,18
d
0,19
2009
99
9,17
0,23
94
8,52
2010
62
9,16
0,29
61
8,52bd
0,24
2011
86
9,19
0,26
83
8,58d
0,22
2012
101
9,07
0,27
94
8,39abd
0,23
2013
23
8,47
0,50
* Within column, LSM values bearing different superscripts differ (P<0,05)
21
7,50
c
0,42
6
The results in Table 6 showed that the alive newborn number/litter in the period of 2002 to 2006 (8.53
to 8.68 piglets/litter) was lower than that in the period of 2007 to 2012 (9.07 to 9, 29 piglets/litter). In 2013,
only 23 litters were monitored so that data were not reflected the true reproductive potential of sows of
VCN03 line. Differences in alive newborn number/litter over the years of 2007 to 2012 was significant (P>
0.05).
Weaned number/litter of each year depended on alive newborn number/litter and survival rate before
weaning. Variation in weaned number/litter of sows of VCN03 line over years was similar to variation in
alive newborn number/litter over years. Thus, weaned number/litter was depended on alive newborn
number/litter. The external factors may also had a great influence on weaned number/litter.
Alive newborn weight/litter, alive newborn weight/piglet, weaned weight/litter and weaned
weight/piglet of sows of VCN03 line by years were presented in table 7.
Table 7: Alive newborn weight/litter, alive newborn weight/piglet, weaned weight/litter and weaned
weight/piglet over years
Alive newborn
Alive newborn
Weaned weight/litter
weaned weight/piglet
weight/litter
(kg)
weight/piglet
(kg)
(kg)
(kg)
Year
n
LSM
SE
n
LSM
SE
n
LSM
SE
n
LSM
SE
2002
28
13,22
0,63
28
1,57ab
0,03
28
64,53a
2,63
28
6,91adc
0,19
2003
44
15,10
0,48
44
1,64b
0,02
43
55,96b
2,04
43
6,25b
0,15
ab
a
cde
0,17
2004
33
15,14
0,54
33
1,58
0,02
32
63,32
2,30
32
6,79
2005
50
14,71
0,46
50
1,55ab
0,02
50
55,78b
1,94
50
6,57bde
0,14
2006
53
13,58
0,44
53
1,56ab
0,02
54
56,03b
1,82
54
6,74cde
0,13
eb
0,09
ab
b
1,22
119
6,46
2007
111
14,48
0,30
111
1,55
0,01
119
55,60
2008
112
14,08
0,30
112
1,52a
0,01
111
57,81b
1,24
111
6,79cd
0,09
2009
94
14,23
0,32
94
1,54a
0,01
94
62,34a
1,33
94
7,98ac
0,10
ab
b
1,61
64
6,48
bde
0,12
2010
61
14,32
0,39
61
1,57
0,02
64
57,45
2011
83
14,62
0,36
83
1,58ab
0,01
89
59,17b
1,45
89
6,60bde
0,11
2012
94
14,03
0,38
94
1,53a
0,02
93
59,19b
1,57
93
6,67de
0,12
21
ab
21
b
21
a
0,21
2013
21
13,06
0,69
1,56
0,03
56,30
2,90
7,28
* Within column, LSM values bearing different superscripts differ (P<0, 05)
Alive newborn weight/litter was the lowest in 2002 and 2006, and was the highest in 2003 and 2004
then was relatively stable in later years. Alive newborn weight/litter over the years was not statistically
different indicating that the year factor did not affect alive newborn weight/litter.
Weaned weight/litter was higher in 2002, 2004 and 2009 (64.53, 63.32 and 62.34 kg/litter) and
significantly differed from weaned weight/litter in later years (P <0.05). Weaned weight/litter in the later
years ranged from 55.60 to 59.19 kg/litter. However, no difference among years was found for most of the
parameters measured.
Weaned weight/litter and weaned weight/piglet considerably varied over years. Breed factor and also
external factors during 12 years were the main reason for the variation.
3.1.3.6. Conclusions and recommendations
a.
Conclusions
Sows of VCN03 line were from "sire line '', which were characterized by lower reproductive
performance.
Alive newborn number/ litter and weaned number/litter of sows of VCN03 line were graduately
decreased from the first generation to the fourth generation (P> 0.05).
7
Alive newborn weight/piglet and weaned weight/piglet were relatively stable over generations.
Weaned weight/litter in the second, thirst and fourth generations was improved (P> 0.05).
Alive newborn number/litter, weaned number/litter, alive newborn weight/litter were lower in the first
parity and increased in the second and thirst parities. From thirst parity to the sixth parity, alive newborn
number/litter, weaned number/litter, alive newborn weight/litter were fluctuated and decreased in the seventh
parity.
Alive newborn number/litter and weaned number/litter in the period of 2007 to 2012 were higher than
these of the period of 2002 to 2006 (P <0.05) due to genetic improvement in this period..
b.
Recommendations
For improvement of reproductive performance of sows of VCN03 line, selection with a higher
pressure, a combination of good feeding, herd management with periodical introduction of new exotic genes
would be necessary.
It would be very critical that heritability and breeding value of reproductive traits of sows need to be
estimated for application in breeding programs
3.2.
The semen quantity and quality of boars of VCN03 sire line
3.2.1.
Introduction
Evaluation of semen quantity and quality of boar is important in the use of sire line. Many boars with a
nice looking have a poor reproductive performance and some can not work as a boar. Therefore, evaluation
of semen quality will help us to indentify some boars with reproductive problems, especially boars used in
artificial insemination and to have any intervention measure for a higher breeding efficiency. Selection for
improvement of quantity and quality of semen of boars in the field has been considered as an important key
factor, and is paid attention by researchers and farmers over the world.
The objective of this study was to determine how and in what extents main factors such as age,
generation, individuals, season and year, affect semen quality and quantity. Semen quantity and quality of
boars of VCN03 sire line was evaluated through two generations in this study.
3.2.2.
Materials and methods
3.2.2.1. Subjects of study
-
22 boars of VCN03 sire line of 2 generations (generation 0: 11 boars in 2006, the generation of 1:
11 boars selected from generation 0).
3.2.2.2. Methods
The study was conducted at Tamdiep pig research and development and research station belonging to
Thuy Phuong Pig Research Centre - National Institute of Animal Science. Data on quantity and quality of
semen of boars from VCN03 sire line was collected from data stored at the station from 2006 to June, 2010
and collected directly from April, 2013 to July, 2010.
Boar semen was collected when boars were 12 months of age and finished when boars was 36 months
of age. Semen boar was collected in the morning using a bar.
Semen volume (V)(ml/collection) was determined using a syringe with a ruler. Sperm motility (A)
was as percentage of sperms moving straight/total sperms observed in the microscope with a magnification
of 100-300 times. A could range from 0 to 1 (or from 0% to 100%). Sperm concentration (C) (millions/ml)
were measured using a machine (SDM5 Minitube, Germany). Total of semen of straight movement (VAC)
was V multiplied by A and by C. Abnormally shaped sperm percentage (K) was determined by staining and
counting with a microscopic detector with a magnification of 400-600 times. pH value of semen was
measured by pH meter (Metter Toledo MP 220).
8
The data were analyzed in a similar way as described in Section 3.1.2.2 with the following
mathematical model:
Yijklm = μ + THi + Dj + Kk + Ml + Nm+ T + εijklm
Where: Yijklm: quantity and quality of semen; μ: population mean; THi: effect of generations (0, 1); Dj:
effect of individual sires (1, 2, ..., 22); Kk: effect of interval between two semen collection (1, 2, 3, 4, 5, 6
days); Ml: effect of seasons (Spring, Summer, Fall, Winter); Nm: effect of the year (2006, 2007, ... .., 2013);
Tijklm: effect (covariance) of age (months); εijklm: random error.
3.2.3.
Results and discussion
3.2.3.1. Factors affecting semen quantity and quality of boars of VCN03 sire line
All factors such as age of semen collection, generation, individuals, breed, season and year affected
semen quality and quantity of boars of VCN03 sire line (P <0.001). However, A, C and K were not
influenced by intervals of two semen collection. Sperm concentration was also not influenced by seasons.
Results of this study were slightly similar to works of Ha Xuan et al. (2013a); Smital, (2009); Wysokinska et
al. (2009); Banaszewska et al. (2007); Milewska et al. (2004).
3.2.3.2. Semen quantity and quality of boars of VCN03 sire line
Semen volume (V), sperm motility (A), sperm concentration (C), abnormally shaped sperm percentage
(K) and VAC of boar semen of VCN03 sire line were 266.49 ml; 84.11%; 282.05 million/ml; 6.28% and
63.72 billion, respectively. Figures of this study were higher than these published by Phan Van Hung and
Dang Vu Binh (2008); Do Duc Luc et al. (2013b) and lower than these published by Ha Xuan Bo et al
(2011); Do Duc Duc et al. (2013a). These figures were similar to the results reported by Ciereszko et al.
(2000); Smital (2009); Wolf and Smital (2009); Wysokinska et al. (2009); Wierzbicki et al. (2010). Semen
quality and quantity of boars of VCN03 sire line rearing at Tamdiep were rather good and met the
temporary national standard for exotic boars in AI programs issued by Ministry of Agriculture and
Rural Development (Decision N01712 QD-BNN, 2008).
3.2.3.3. Semen quantity and quality of boars of VCN03 sire line over seasons
Semen volume (V), sperm motility (A), sperm concentration (C), abnormally shaped sperm percentage
(K) and VAC of boar semen of VCN03 sire line in the season (spring, summer, autumn, winter) were
presented in Table 10. V, A of semen were higher in spring and summer, lower in autumn and winter. VAC
was higher in spring and summer, lower in the fall and winter. Abnormally shaped sperm percentage was the
lowest in spring and winter, the highest in the fall and summer.
Table 10: Semen population and quality of boars of VCN03 sire line over seasons
Spring
(n = 809)
LSM
SE
Indicators
Semen volume (ml)
Sperm motility (%)
Sperm
concentration
(millions/ml)
VAC (billions/time)
Abnormally
percentage (%)
shaped
Summer
(n = 788)
LSM
SE
Autumn
(n
= 805)
LSM
SE
Winter
(n = 858)
LSM
SE
264,82a
85,79a
7,62
0,89
264,99a
85,23a
5,56
0,65
259,70b
83,60b
3,63
0,42
257,60b
84,08b
2,05
0,24
273,40
63,39a
7,10
2,69
274,09
63,37a
5,17
1,96
273,14
60,39b
3,38
1,28
275,56
61,34ab
1,91
0,73
6,21b
0,20
6,29ab
0,15
6,36a
0,10
6,21b
0,05
sperm
* Within column, LSM values bearing different superscripts differ (P<0, 05)
9
According to Smital (2009), Ha Xuan Bo et al. (2011) semen quality of Pietrain boars was the best in
the winter and next spring to autumn and the lowest in summer. Wierzbicki et al. (2010) also showed that C,
A and VAC in the winter (642.02 million/ml, 72.68% and 94.14 billion/times) were higher than these in
summer (590.87 million/ml, 72.51% and 92.72 billion/time) and that V was not affected by months of the
year. According to Ha Xuan Bo et al. (2013a) Pietrain pigs had a better tolerance to stress in spring and their
tolerance to stress was reduced in the summer. The research results of Do Duc Luc et al. (2013) also showed
that C was the lowest in July (summer) and was the highest in October and November (winter).
Thus, semen quantity and quality of boars of VCN03 sire lines kept in Tamdiep pig research and
development station in four seasons (spring, summer, autumn and winter) were slightly different from semen
quantity and quality of boars reported by several authors. This difference was partly due to the differences in
breeds used and external conditions such as macro and micro climatic conditions...where boars were reared.
3.2.3.4. Semen quantity and quality of boars of VCN03 sire line over years
Semen quantity and quality of boar of VCN03 sire line over years were presented in Table 11. Semen
quantity and quality of boars of VCN03 sire line were greatly varied over years. Differences in semen
quantity and quality of boars of VCN03 sire line over the years were statistically significant (P <0.001).
Table 11: Sperm quantity and quality of boars of VCN03 sire line over years
Year
2006
2007
2008
2009
2010
2011
2012
Semen volume
(ml)
LSM
264,57bc
258,79bc
248,20c
270,65ab
256,12bc
270,86a
263,24bc
SE
30,37
21,69
13,14
5,23
5,49
13,63
22,20
Sperm
motility (%)
LSM
91,34a
90,79a
86,11b
86,45b
81,15c
79,24c
77,64c
SE
3,55
2,54
1,54
0,61
0,64
1,59
2,60
Sperm
concentration
(millions/ml)
LSM
247,21b
294,02a
278,26ab
280,47ab
264,45ab
276,93ab
276,98ab
SE
28,29
20,20
12,24
4,87
5,11
12,70
20,68
VAC
(billions/time)
LSM
63,96ab
70,15a
60,50b
67,82a
55,68b
59,38b
57,37b
SE
10,74
7,67
4,65
1,85
1,94
4,82
7,85
Abnormally
shaped sperm
percentage (%)
LSM
SE
c
6,09
0,80
ab
6,43
0,57
c
6,13
0,34
bc
6,20
0,14
b
6,26
0,14
a
6,53
0,36
b
6,24
0,58
* Within column, LSM values bearing different superscripts differ (P<0, 05)
3.2.3.5. Semen quantity and quality of boars of VCN03 sire line over generations
Semen quantity and quality of boars of VCN03 sire line over generations were presented 12.
Table 12: Semen quantity and quality of boars of VCN03 sire line over generations
Generation 0
Generation 1
(n = 1720)
(n = 1540)
Parameters
P
LSM
SE
LSM
SE
Semen volume (ml)
256,03a
11,71
267,52b
19,87
<0,0001
a
b
Semen motility (%)
78,23
1,37
91,12
2,32
<0,0001
a
b
Sperm concentration (millions/ml)
270,80
10,91
277,29
18,51
<0,0001
a
b
VAC (billions/time)
54,98
4,14
69,26
7,03
<0,0001
a
b
Abnormally shaped sperm percentage (%)
6,51
0,31
6,03
0,52
<0,0001
* Within column, LSM values bearing different superscripts differ (P<0, 05)
Results showed semen volume, sperm motility and sperm concentration of boars of VCN03 sire line in
the first generation were significantly improved compared to these in the zero generation. Therefore, VAC in
the first generation was markedly improved and, increased by 14.28 billion/time (P <0.0001). Abnormally
shaped sperm percentage in the first generation was also markedly decreased by 0.48% (P <0.0001).
10
Improvement of semen quantity and quality of boars of VCN03 sire line in the first generation was
partly due to selection effort and improved rearing conditions.
3.2.3.6. Conclusions and recommendation
a.
Conclusions
Semen quality and quantity of boars of VCN03 sire line were rather good and met the temporary
national standard for exotic boars in AI programs issued by Ministry of Agriculture and Rural
Development (Decision N01712 QD-BNN, 2008).
Selection combined with improvement in environmental condition (nutrition, feeding, housing ...)
increased semen quantity and quality of boars in the first generation.
b.
Recommendations
Heritability and estimated breeding value of fertility traits of boars need to be regularly and
continuously determinated. So that heritability and estimated breeding value of fertility traits of boars can be
able to efficiently apply in breeding programs.
3.3.
Growth, performance and meat quality of boar of VCN03 sire line
3.3.1.
Introduction
VCN03 sire line (White Duroc) plays a key role in the breeding program of the PIC Vietnam. This sire
line was used for crossing with two grand parent pig lines (VCN11, VCN12) to produce parent line (VCN21,
VCN22). This sire line has some advantages such as a high potential of growth, lower feed conversion ratio
(FCR), higher marbling score and high reproductive performance. However, so far, growth, performance,
quality of meat of pigs of VCN03 sire line have not been systematically investigated. Therefore, assessment
of growth, performance, quality of meat of pigs of VCN03 sire line over generations is essential.
Objectives of this study was to evaluate growth, performance, quality of meat of pigs of VCN03 sire
line in two generations and to see the initial selection efficiency.
3.3.2.
Materials and methods
3.3.2.1. Subjects of study
205 non-castrated boars (generation 0: 114 boars, generation 1: 91 boars) were used in this study.
Carcass evaluation was conducted on 40 non-castrated boars (generation 0: 20 boars, generation 1: 20 boars)
and meat quality evaluation was performed on 36 non-castrated boars (generation 0: 17 boars, generation 1:
19 boars).
3.3.2.2. Methods
The study was conducted at Tamdiep pig research development station belonging to Thuy Phuong Pig
Research Centre - National Institute of Animal Science. Data on growth, performance and meat quality of
boars of VCN03 line was obtained from data base stored from 2002 to June, 2010 and collected directly from
July, 2010 to April, 2013.
Body weight of each animals was determined using Kelba electronic scales (Australia) at the start and
at the end of the experiment. Average daily gain (g/day) (ADG) was calculated based on the difference
between body weight at the end of experiments and body weight at the start of experiments. Back fat
thickness and loin muscle thickness were measured at the end of the experiment using ultrasound equipment:
Agroscan AL with the ultrasound probe Alal 350 (ECM, France) in position of thirst and fourth ribs,
according to the method described in the study of Youssao et al. (2002). Back fat thickness and loin muscle
thickness were used to estimate the proportion of lean meat using the regression equation recommended by
Belgium Ministry of Agriculture in 1999.
Y = 59,902386 - 1,060750 X1 + 0,229324 X2
11
Where: Y: estimated lean percentage (%); X1: back fat thickness including skin (mm); X2: loin muscle
thickness (mm).
Carcass weight was weighted using a scale (100 kg) after removing hair, blood and organ. Dressing
percentage was calculated based on body weight before slaughter and carcass weight. Dressing percentage =
(Carcass weight/slaughter weight) x 100.
Meat quality was measured in Department of Animal Genetics and Breeding, Faculty of Animal
Science and Aquaculture, Vietnam University of Agriculture. Parameters measured included: pH45 values
(pH of loin muscle at 45 min after slaughter) and pH24 (pH of loin muscle preserved in 24 hours after
slaughter), meat color, dehydration percentage in preservation. Meat processing was according to the
method of Warner et al. (1997), meat toughness was measured by method of Channon et al. (2003). The pH
value was measured using Testo 230 (Germany) at the time of 45 minutes (pH45) and 24 hours (pH24) after
slaughter. The pH value was the mean of 5 measurements in 5 different points.
Meat color was measured using a Minolta CR-410 (Japan) with indexes: L* (lightness) , a* (Redness)
and b* (yellowness) at 24 hours (24 L*, a* 24, b* 24) after slaughter. Dehydration percentage in preservation
and processing (%) were determined based on the sample volume before, after storage, processing at the time
of 24 hours. Loin toughness (N) was determined using 2000D Warner Bratzler machine (USA) at 24 hours
after slaughter preservation. Meat quality was classified on dehydration percentage in preservation, light
meat (L*), pH45, pH24 values according to standards of Warner et al. (1997), Joo et al. (1999). Good quality
pork would have dehydration percentage in preservation of 2-5%, light meat (L*) of 40-50, pH45 values of
more than 5.8 and pH24 of less than 6.1 and of higher than 5.4.
Data was analyzed as described in 3.1.2.2 section using mathematical model: yij = μ + ai + bxij + eij
Where: yij: jth observation in the formula i, μ: population mean, ai: effect of generation i, bxij: covariance:
effect of age at beginning of experiment (for weight of start experiment) or age at the end of the experiment
(for growth, carcass and meat quality, except weight at the beginning of experiment). eij: random error.
3.3.3.
3.3.3.1.
Results and discussion
Growth and meat production of boars of VCN03 sire line
Average body weight at 60 day old and average body weight at end of the experiment were 22.38 and
99.48 kg, respectively. ADG (g/day) from birth to end of the experiment, from 60 day old to the end of
experiment, back fat thickness, loin muscle thickness, lean meat percentage of boars of VCN03 sire line
were 621.04 g/day; 796.18 g/day; 9.88 mm; 47.71 mm and 60.37%, respectively. Body weight at 60 day old
of boars of VCN03 sire line in this study was higher than that of Pietrain boars (Do Duc Luc et al. (2013).
ADG (g/day) of boars of VCN03 sire line in individual tests (796.18 g/day) was higher than that reported by
Pham Thi Dung (2005); Chen Weng Guang et al. (1997) in Duroc boars and higher than that reported by Do
duc Luc et al. (2008); Zhang et al. (2011); Ha Xuan Bo et al. (2013a) in Pietrain. ADG (g/day) from birth to
the end of experiment and ADG in individual tests of boars of VCN03 sire line were higher than these of
reported by Phung Thi Van et al. (2001); Phan Xuan Hao (2002); Pham Thi Kim Dung (2005); Zhang et al.
(2011).
Back fat thickness of boars of VCN03 sire line (9.88 mm) was higher than that of stress resistance
Pietrain boars (8.00 mm) (Ha Xuan Bo et al., 2013b; Do Duc Luc et al., 2013; Trinh Hong Son et al., 2012).
Loin muscle thickness of boars of VCN03 sire line (47.71 mm) was similar to that Pietrain boars (Do Duc
Luc et al., 2011) and lower than that of DuPi and PiDu hybrid boars (Trinh Hong Son et al., 2012). Lean
meat percentage of boars of VCN03 sire line was higher than the published results of Phan Xuan Hao
(2007); Nguyen Van Duc et al. (2010); but similar to the results reported by Bidanel et al. (1991); Marinus et
12
al. (2010); Werner et al. (2013) and lower than the published results of Werner et al. (2010); Ha Xuan Bo et
al. (2013b).
3.3.3.2.
a.
Growth rate and meat production of boars of VCN03 over 2 generations
Growth rate of VCN03 over 2 generations
The first selected generation had a higher ADG in individual (60.09 g/day) than that of the zero
generation and difference in ADG between two generations was statistically significant (P <0.001). A great
improved ADG of the first generation was due to the first application of estimated breeding values of boars
of VCN03 in a selection program and an improvement of feeding, housing...
According to Kazuo Ishii et al. (2005), ADG of Shimofuri Red Boar line (Duroc) after 7 generations
of selection was enhanced by 243 g/day. Giang Hong Tuyen (2008) showed that ADG of Mong Cai pigs was
increased by 27.95 g/day (7.45%) after 4 generations of selection.
b.
Meat performance of boars of VCN03 sire line over 2 generations
Dressing percentage of boars of VCN03 sire line (80.68 to 81.26%) was higher than that published by
Werner et al. (2013); Phan Xuan Hao (2007); Phan Van Hung and Dang Vu Binh (2008). Back fat thickness
of the first generation (9.38 mm) was lower than that of the zero generation (10.27 mm). Loin muscle
thickness and lean meat percentage of the first generation was higher than that of the zero generation (48.80
vs. 46.84 mm and 61.14 vs. 59.74%. Thus, after one generation selection, back fat thickness and loin muscle
thickness and lean meat percentage were improved. According to Kazuo Ishii et al. (2005), back fat thickness
of Shimofuri Red boar line (Duroc) after 7 generations of selection was reduced by 0.8 mm. Lo et al. (2008)
reported that carcass meat, lean meat percentage of Duroc and Landrace castrated boars raising in Taiwan
were 84.18 and 83.39, 47.64 and 46.36%, respectively. Ha Xuan Bo et al. (2013b) reported that carcass meat,
dressing percentage and lean meat percentage of Pietrain castrated boars were 80.21; 65.40 and 63.51%,
respectively. It was showed that, after one generation selection, back fat thickness of boars of VCN03 sire
line was reduced and lean meat percentage were improved.
3.3.3.3. Meat quality of boars of VCN03 sire line
a.
Meat quality of boars of VCN03 sire line
pH45 and pH24 values of loin muscle of boars of VCN03 sire line in this study were 6.15 and 5.50,
respectively. Value light (L*), red (a*) and yellow (b*) of meat were 54.06; 15.02 and 7.11, respectively; and
were within the standard of good quality meat. Water loss percentage after 24 hours storage of meat of boars
of VCN03 sire line was 1.86%. This finding was consistent with publications of Phan Xuan Hao (2007,
2009; Ruusunen et al., 2007; Kyla-Puhu et al., 2004; Channon et al., 2003; Nguyen Van Thang, Dang Vu
Binh, 2006; Morlein et al., 2007; Alonso et al., 2009; Pas et al., 2010; Heyer et al., 2005; Phan Xuan Hao
and Nguyen Van Chi, 2010; Edwards et al., 2003; Peinado et al., 2008; Phan Xuan Hao and Hoang Thi
Thuy, 2009; Ha Xuan Bo et al., 2013b). Meat quality of boars of VCN03 sire line based on water loss
percentage after 24 hour storage, meat light (L), pH45 and pH24 values of loin muscle and criteria of Warner
et al. (1997), Joo et al. (1999), Van Laak and Kauffmanf (1999), was a good quality meat.
b.
Meat quality of boars of VCN03 sire line over generations
pH45 value of loin muscle of boars of VCN03 sire line in the first generation was lower than that of
the zero generation (P <0.05), but pH24 value of loin muscle of boars of VCN03 sire line in the first
generation was lower than the zero generation (P> 0.05).
It appeared that meat quality was negatively correlated with ADG of pigs. Increased ADG was
associated with decreased meat quality (Latorre et al., 2003). In this study, higher ADG of boars in the first
13
generation may be a cause of lower pH value. However, pH45 and pH24 values of loin muscle of boars of
VCN03 sire line in both generations were in a range of good quality meat.
Meat quality of boars of VCN03 sire line over two generations in this study was good according to
standards of Warner et al. (1997), Joo et al. (1999).
3.3.3.4. Conclusion and recommendation
a.
Conclusion
Boars of VCN03 sire line had ADG of 796.18 g/day in the period of 22.48 to 96.30 kg, low back fat
thickness (9.88 mm) and a high lean meat percentage (60.37%). Meat quality of boars of VCN03 sire line
was in a range of good quality meat.
After one generation selection, growth rate, meat production and quality were slightly improved.
b.
Recommendation
Heritability and estimated breeding value of fertility traits of boars need to be regularly and
continuously determinated. So that heritability and estimated breeding value of fertility traits of boars can be
able to efficiently apply in breeding programs.
Chapter IV
HERITABILITY AND ESTIMATED BREEDING VALUE
4.1.
Introduction
Pig breeding was carried out mainly by the method of phenotypic selection of phenotypic traits and
mating pairing to avoid inbreeding. For this reason, the genetic progress obtained was not as high as
expected. In recent years, the use of breeding value has been started and applied in a limited number of pig
breeding farms. So far there has been a few works publishing estimated breeding values of different traits of
pigs in Vietnam (Kieu Minh Luc, 2001; Nguyen Ngoc Tuan and Tran Thi Dan, 2001; Ta Thi Bich Duyen,
2003; Tran Van Chinh, 2004; Nguyen Thi Xa, 2005; Nguyen Van Hung and Trinh Cong Thanh, 2006; Pham
Thi Kim Dung and Ta Thi Bich Duyen, 2009; Ta Thi Bich Duyen et al., 2009).
The objectives of this research was to calculate heritability and estimated breeding value of some
reproductive traits of sows of VCN03 sire line and growth rate and meat quality traits of boars of VCN03
sire line. Estimated breeding value would be the basis for selection programs aiming at improving
productivity and quality of VCN03 sire line.
4.2.
Materials and methods
4.2.1.
Subjects of study
- 362 sows with the 1129 litters and non-castrated boars of VCN03 sire line, including 205 boars (The
zero generation: 114 boars, the first generation: 91 boars) were used.
4.2.2.
Methods
Data collection was described in Section 3.1.2.2 and 3.3.2.2. Estimation of variance components,
heritability and breeding value were done using REML method (Restricted Maximum Likelihood),
MTDFREML software. The mathematical model was as follows:
y = Xb + Za + e, V
=
Where: y: Observered vector of studied traits, b: Vector of fixed elements (generation, age, year), a:
vector of additive genetic value, e: Vector of random error, X: Matrix of fixed elements, Z: Matrix of random
element, A: Matrix of additive correlation among individuals,
: additive genetic variance,
: maternal
14
genetic variance,
: external variance. For alive newborn weight /piglet and newborn weight/litter traits
model was filled with b where b: number of weaned piglets/litter and weaned age.
"Starting value" was estimated on previous studies. The estimated parameter included: genetic
variance ( ), maternal genetic variance ( ), external variance ( ), phenotypic variance ( ), heritability
( ) and estimated breeding values (EBV) of the above studied traits.
4.3.
Results and discussion
4.3.1.
Heritability
4.3.1.1.
Heritability of some reproductive performance traits of sows of VCN03 sire line
Additive genetic variance, maternal genetic variance, external variance, phenotypic variance,
heritability and maternal additive genetic coefficients for alive newborn number/litter, weaned
number/litter, alive newborn weight/litter, alive newborn weight/piglet, weaned weight/litter and weaned
weight/piglet of sows of VCN03 sire line were presented in Table 18. It was showed that additive genetic
and maternal genetic heritabilities of sows of VCN03 sire line were low.
Table 18: Additive genetic coefficient ( ), maternal genetic variance ( ), external variance ( ),
phenotypic variance ( ), additive genetic coefficients ( ) and maternal genetic coefficients ( ) of
some reproductive performance traits of sows of VCN03 sire line
2A
2M
2E
2P
h2A
h2M
Alive newborn number



5,53197
0,19 ± 0,011
0,12 ± 0,051
Weaned number



2,31813
0,11 ± 0,035
0,01 ± 0,001
Alive newborn
weight/piglet
0,00160
0,00095
0,01070
0,01325
0,12 ± 0,053
0,07 ± 0,004
Newborn weight/litter
0,10329
0,03643
0,92284
1,06256
0,10 ± 0,006
0,03 ± 0,049
Weaned weight /piglet
0,09573
0,14490
0,60192
0,84255
0,11 ± 0,008
0,17 ± 0,058
Weaned weight /litter
4,26662
0,733
44,67607
59,67581
0,24 ± 0,052
0,01 ± 0,001
Parameter
Additive genetic coefficient ( ) of alive newborn number, weaned number, alive newborn
weight/piglet, newborn weight/litter, weaned weight /piglet traits were low and they were 0.19; 0.11; 0.12;
0.10 and 0.11, respectively. Maternal genetic coefficient ( ) of alive newborn number, weaned number,
alive newborn weight/piglet, newborn weight/litter, weaned weight /piglet and weaned weight/litter were
also low and they were 0.12; 0.01; 0.07; 0.03; 0.17 and 0.01, respectively. Heritability values in this study
were consistent with published works of Hermesch et al. (2000); Hanenberg et al. (2001); Chen et al.
(2003); Hamann et al. (2004); Arango et al. (2005); Rho et al. (2006); Imboonta et al., (2007); Damgaard et
al. (2003); Holm et al. (2004); Nguyen Huu Tinh (2009); Schneider et al. (2011) and were higher than these
in reports of Smiltal et al. (2005) and Lundgren et al. (2010).
Reproductive perfromance traits of sows of VCN03 sire line had a low
and
heritability. So
that improved selection woud be inefficient. It would be important that selection needs to be combined with
an improvement of environmental conditions.
4.3.1.2.
Heritability of growth and meat productivity of boars of VCN03 sire line.
Genetic variance ( ), external variance ( ), phenotypic variance ( ) and heritability ( ) of body
weigh at 60 day old, body weight at the end of expriment, daily weight gain, back fat thickness, loin muscle thickness and
lean meat percentage of boars of VCN03 sire lines were presented in Table 19. While heritability of body
weight at 60 day old trait was low (0.17), heritability of loin muscle thickness (h2 = 0.58) and lean meat
15
percentage traits (0.56) were high. Heritability of traits such as ADG; back fat thickness and body weight at
the end of the experiment were medium and they were 0.34; 0.34 and 0.22, respectively.
The higher the heritability of traits was, the more efficient the selection was.
Table 19. Genetic variance ( ), external variance ( ), phenotypic variance ( ) and heritability ( ) of
body weigh at 60 day old, body weight at the end of expriment, daily weight gain, back fat thickness, loin muscle
thickness and lean meat percentage of boars
Parameter
Body weight at 60 day old
0,324
1,580
1,904
0,17 ± 0,156
Body weight at the end of experiment
7,336
25,416
32,753
0,22 ± 0,172
418,946
829,388
1248,334
0,34 ± 0,199
Back fat thickness
0,834
1,633
2,467
0,34 ± 0,199
Loin muscle thickness
15,893
11,424
27,317
0,58 ± 0,239
Lean meat percentage
2,350
1,826
4,176
0,56 ± 0,209
Daily weight gain (ADG)
Heritability of some traits in this study was in an agreement with works of Tomiyama et al. (2012);
Gu et al. (1989) (cited by Clutter, 1998); Tran Thi Minh Hoang et al. (2008a); Kiszlinger et al. (2011);
Saintilan et al. (2011); Tomka et al. (2010); Szyndler-Nedza et al. (2010); Radovic et al. (2013). Heritability
of back fat thickness trait in our study (h2 = 0.34) was lower than that published by other authors. Tran Thi
Minh Hoang et al. (2008a) reported that heritability of back fat thickness traits of Yorkshire and Landrace
breeds was 0.45. According to Nguyen Huu Tinh (2009), heritability of back fat thickness traits of Landrace
and Yorkshire pigs at 90 kg was 0.47 and 0.60 respectively.
4.3.2.
Estimated breeding value-EBV
4.3.2.1.
EBV for some reproductive performance traits of sows of VCN03 sire line
4.3.2.1.1.
EBV for alive newborn number trait
While EBV for the groups with 5 % of the best animals (18 animals) was 0.987, EBV for the groups
with 10, 20, 30 and 50% of best animals was slightly lower and these groups had 32; 72; 109 and 181
animals, respectively. Average EBV was different from one group to another and from one individual to
another. Therefore, the identification of individuals with a higher EBV for a selection program would be
very necessary and meaningful. For example, EBV of five individuals with identification numbers of 3597,
3826, 3110, 3003 and 3001 were 1.551; 1.300; 1.223; 1.117 and 1.113, respectively.
4.3.2.1.2.
EBV for weaned number trait
Absolue value of EBV for weaned number trait ranged from -0.717 to +1.115 and overall mean of
EBV for weaned number trait was -0.001. The average accuracy of estimation of this EBV was high (>
50%) and higher than that of EBV for newborn number trait. EBV for weaned number was not different so
much from one group to another and from one individual to another. EBV for weaned number trait and
accuracy of estimation of the best 5 individuals with indentification numbers of 3597, 3492, 3834, 3583 and
3829 were 1.115; 0.666; 0.645; 0.601; 0.590 and 0.68; 0.71; 0.63; 0.68; 0.64, respectively.
4.3.2.1.3.
EBV for alive newborn weight/litter
Absolute value of EBV for alive newborn weight/litter trait ranged from -0.260 to +0.415 and overall
mean of EBV for alive newborn weight/litter was +0.009. EBV for newborn weight/litter trait and accuracy
16
of estimation of the best 5 individuals with indentification numbers of 3449, 3107, 4025, 3100 were 0.415
0.394; 0.393; 0.351; 0.317 and 0.51; 0.55; 0.55; 0.53 and 0.52, respectively.
4.3.2.1.4.
EBV for alive newborn weight/piglet
Absolute value of EBV for alive newborn weight/piglet trait ranged from -0.034 to +0.066 and overall
mean of EBV for alive newborn weight/piglet trait was +0.001. EBV for alive newborn weight/piglet trait
and accuracy of estimation of the best 5 individuals with indentification numbers of 3449, 3100, 3107, 4025
and 3538 were 0.066; 0.065; 0.050; 0.040; 0.035 and 0.53; 0.54; 0.56; 0.55; 0.61, respectively.
It was found that among 5 individuals with higher EBV for alive newborn weight/piglet trait, 4 of 5
individuals also had a higher EBV for newborn weight/liter trait. It was indicated that EBV of two traits was
close associated and positively correlated with each other.
4.3.2.1.5.
EBV for weaned weight/litter
EBV for weaned weight/litter trait and accuracy of estimation were the highest among EBV and
accuracy of estimation for other reproductive perfomance traits in this study. Vaiation of average EBV of
this trait was small from one group to another and from one individual to another. For example, group with
5% of best individual and group with 10% of best individual had EBV of 3.930 and 3.359. Difference in
EBV between two groups was only below 8,55. EBV for weaned weight/liter trait ranged from -6.407 to
+6.401 and overall mean of EBV for weaned weight/litter trait was +0.074. Accuracy of EBV estimation of
groups with 5; 10; 20; 30% of the best individuals were over 60%. Accuracy of EBV estimation of the group
with 50% of the best individuals was 55.8%.
EBV for weaned weight/litter trait and accuracy of estimation of the best 5 individuals with
indentification numbers of 4042, 3005, 3990, 3607; 3007 were 6.401; 5.272; 4.174; 4.087; 3.892 and 0.51;
0.57; 0.75; 0.73; 0.71, respectively.
4.3.2.1.6.
EBV for weaned weight/piglet
EBV for weaned weight/piglet trait was lower than that for weaned weight/litter trait. Difference in
EBV among groups was not so high. For example, group with 5% of best individual and group with 10% of
best individual had EBV of 0.219 and 0.186. Difference in EBV between two groups was only 8.49%. EBV
for weaned weight/piglet ranged from -0.378 to +0.350 and was +0.004, on average. EBV for weaned
weight/piglet trait and accuracy of estimation of the best 5 individuals with indentification numbers of 4042,
3005, 3607, 3665 and 4059 were 0.350, 0.301; 0.292; 0.226; 0.220 and 0.48; 0.39; 0.49; 0.45; 0.48,
respectively.
4.3.2.2.
Estimated breeding values for growth and meat productivity traits of boars of VCN03 sire line
4.3.2.2.1.
EBV for body weight trait at 60 day old trait
For body weight at 60 day old trait, it was prefered to chose individuals with a positive highest EBV.
The range of EBV for body weight at 60 day old was the smallest (-0.579 to +0.774) and overall EBV was
+0.102. However, accuracy of EBV estimation for this trait was low (approximately 0.50). The group with
1% of the best individuals including Y259 and Y232 boars had EBV of +0.774 and +0.747.
4.3.2.2.2.
EBV for body weight at the end of experiment
The range of EBV for the trait of body weight at the end of this experiment and accuracy of estimation
were higher than these of body weight at 60 day old trait. EBV for the trait of body weight at the end of this
experiment ranged from -2.824 to +5.096 and overall mean of EBV for the trait of body weight at the end
of this experiment was +0.361. The accuracy of estimation of EBV for groups with 1% to 50% of the best
individuals was above 0.50. The group with 1% of the best individuals including Y234 and Y277 boars had
EBV of +5.096 and +3.457.
17
4.3.2.2.3.
EBV for ADG trait
While EBV for ADG trait of the group with 1% of best individuals was so much different form that of
other groups, difference EBV for ADG trait among other group was not so large. The group with 1% of the
best individuals including Y234 and Y232 boars had EBV of +43.759 and +37.294. There were a relatively
large differences in EBV within groups, the more animal in the group was, the larger the difference in EBV
was. Difference in EBV between individuals having the highest EBV and the lowest EBV in the group with
1% of the best individuals was 1.17 times. Similarly, these figures for groups with 5; 10; 20 and 50% of the
best individuals were more than 1.93; 2.59; 3.95 and 15.31 times, respectively. The accuracy of EBV
estimation was high. The accuracy of EBV estimation of the groups with 1 to 50% of the best individuals
was 0.60.
4.3.2.2.4.
EBV for back fat thickness trait
Absolute value of EBV for back fat thickness trait of boars of VCN03 sire lines ranged from -1.331 to +1.563 and overall mean of EBV for back fat thickness trait of boars of VCN03 sire lines was
+0.053. Y149 and Y147 boars in the group with 1% of the best individuals had the lowest negative EBV for
this trait (-1.331 and -1.270) and average EBV of this group was -1.301 with an accuracy of 0.63. Similarly,
EBVs of groups with 5, 10, 20 and 50% of the best individuals were -0.96; -0.801; -0.622; -0.341,
respectively. Groups with 5, 10, 20 and 50% of the best individuals had 10, 21, 41 and 103 animals,
respectively. Accuracy of EBV estimation for al above groups was 0.69.
4.3.2.2.5.
EBV for loin muscle thickness trait
EBVs for loin muscle thicness trait of Y234 and Y248 boars of VCN03 sire line in group with 1% of
the best individuals was +10.368 and +8.553. EBVs for loin muscle thicness trait of boars of VCN03 sire
line in group with 1 and 50% of the best individuals was similar. EBVs for loin muscle thicness trait of
boars of VCN03 sire line were different from one group to another and were considerablly different from one
animal to another wthin the same group. For example, differnce in EBVs between animals having the highest
and lowest EBVs in the group with 10% of the best individuals was nearly 2 times. Differnce in EBVs
between animals having the highest and lowest EBVs in the later groups was much higher. Differnce in
EBVs between animals having the highest and lowest EBVs in the group with 50% of the best individuals
was 12.93 times. Accuracy of EBV estimation for loin muscle thickness trait was the highest compared to
that of other traits such as ADG, lean meat percentage, back fat thickness, body weight at 60 day old and
body weight at the end of the experimenthighest. Accuracy of EBV estimation in the group with 1 to 50% of
the best individuals was 0.70.
4.3.2.2.6.
EBV for lean meat percentage trait
EBV for lean meat percentage trait of the groups with 1 to 50% of the best individuals was positive.
EBV for lean meat percentage trait of boars of VCN03 sire line ranged from -2.174 to +2.817 and overall
mean of EBV for lean meat percentage trait of boars of VCN03 sire line was +0.178.
EBVs of Y238 and Y151 boars in the group with 1% of the best individuals were +2.817 and +2.605;
these individuals were in the nucleus herd. Accuracy of EBV estimation for lean meat percentage trait of the
groups with 1% to 50% of the best individuals was high (over 0.72). The accuracy of EBV estimation for
lean meat percentage trait was lower than that of for loin muscle thickness trait and lower than that for back
fat thickness trait.
4.4.
Conclusion
4.4.1.
Heritability of reproductive performance trait, growth and meat productivity traits of sows and
boars of VCN03 sire line.
Heritability of reproductive performance traits including alive newborn number/litter, weaned
number/litter, alive newborn weight/piglet, alive newborn weight/litter and weaned weight/piglet of sows of
18
VCN03 sire line was low and was 0.19; 0.11; 0.12; 0.10 and 0.11, respectively. Only heritability of weaned
weight/litter trait was medium (0.24).
Heritability of loin muscle thickness and lean meat percentage traits was high and was 0.58 and 0.56,
respectively. While heritability of ADG, back fat thickness and weight gain in the end of the experiment
traits was medium (0.34; 0.34 and 0.22), heritability of body weight at 60 day old trait was low (0.17).
4.4.2.
Estimated breeding values on reproductive performance, growth and meat potential of VCN03
boar line.
EBVs for reproductive performance traits of sows of VCN03 sire line in the group with 5% of the best
individuals were the highest. Average accuracy of EBV estimation for traits such as alive newborn
number/litter, weaned number/litter, and weaned weight/litter of sows of VCN03 sire line in the groups with
5% to 50% of the best individuals was higher than 0.50.
Accuracy of EBV estimation for traits such as growth and meat productivity ranged from medium to
high. Accuracy of EBV estimation for traits such as growth and meat productivity in the group with 1% of
the best individuals was rather high and ranged from 0.45 to 0.79.
Chapter V
GENERAL DISCUSSION
5.1.
Productivity of VCN03 sire line
5.1.1.
Reproductive performance of sows of VCN03 sire line.
Sows of VCN03 line was in the group of "sire line'' and their reproductive performance was lower
than published results of Imboonta et al. (2007); Nguyen Huu Tinh, (2009); Phung Thi Van et al. (2001).
Thus, reproductive performance of sows of VCN03 sire line was lower than most of Landrace and Yorkshire
sows in Vietnam, and they were suitable for use as sows of "sire line'' to produce parental pigs.
Two traits: alive newborn number/litter and weaned number/litter of sows VCN03 line appeared to
be decreased over generations. However, differences in alive newborn number/litter and weaned
number/litter of sows VCN03 line between two generations were not statistically significant indicating that
reproductive performance sows of VCN03 sire line was relatively stable. As discussed some where, the
efficiency of selection in past year was not as high as expected. For the above reason, the determination of
heritability of some reproductive traits and EBV in sows were an urgent need for improving productivity of
VCN03 sire line.
5.1.2.
Semen quantity and quality of boars of VCN03 sire line
While V, A, C and VAC of semen of boars of VCN03 sire line were higher than these of boars of L,
Y, Du, Pi, and PiDu hybrids (25, 50 and 75% of Pietrain blood), abnormally shaped sperm percentage of
semen of boars of VCN03 sire line was also higher than that of of boars of L, Y, Du, Pi, and PiDu hybrids
(25, 50 and 75% of Pietrain blood) raised in Vietnam. However, quality and quantity of semen of boars of
VCN03 sire line were lower than these of Pietrain boars raised in Vietnam (Ha Xuan Bo et al., 2011).
Semen quantity and quality of boars of VCN03 sire line met the temporary national standard for
exotic boars in AI programs issued by Ministry of Agriculture and Rural Development (Decision
N01712 QD-BNN, 2008).
Semen quantity and quality of VCN03 sire line after one generation selection were improved
(P<0.0001) indicating that selection was the efficient way. However, variation in semen quality and quantity
was still large and strongly influenced by seasonal factors, years. Therefore, in order to stabilize and improve
19
the productivity and semen quality of boars of VCN03 sire line, selection needs to go hand in hand with a
external condition improvement
5.1.3.
Growth, performance and meat quality of VCN03 sire line
ADG of boars of VCN03 sire line was higher than published results of Do Duc Luc et al. (2008); Ha
Xuan Bo et al. (2013a); Phung Thi Van et al. (2001); Phan Xuan Hao (2002). Dressing percentage of boars
of VCN03 sire line was also higher than published results of Werner et al. (2013); Phan Xuan Hao (2007).
Lean meat percentage of boars of VCN03 sire line was higher than published results of Nguyen Van Duc et
al. (2010) and similar to works done by Bidanel et al. (1991); Marinus et al. (2010); Werner et al. (2010).
Meat quality of boars of VCN03 sire line was good according to criteria of Warner et al. (1997), Joo et al.
(1999), Van Laak and Kauffmanf (1999).
5.2.
Heritability and estimated breeding value
5.2.1.
Heritability and estimated breeding value of some reproductive performance traits of sows of
VCN03 sire line
Heritability of reproductive performance traits of sows of VN03 sire line was low and was from 0.10
to 0.19. This was normal, because reproductive performance traits was considerably affected by
environmental factors. The low heritability of reproductive performance traits of sows explained why
efficiency of selection for these traits was low in past years. The results also demonstrated thats selection
approach in past years was not appropriate because the population was not large enough and the genetic
evaluation was not conducted regularly.
From this study, 5% of sows with best EBV for reproductive traits were selected and put in a
nucleus herd as a source of genetic materials to improve productivity and quality of sows of VCN03 sire line.
From these results, it could be concluded for enhancement of reproductive performance of sows of VCN03
sire line at Tamdiep pig research and development station, determined heritability and EBV for reproductive
perfomance traits need to be involved in selection programs in a combination with new genetic materials
introduction and external condition improvement.
5.2.2.
Heritability and estimated breeding value for growth and meat productivity traits of boars of
VCN03 sire line
Heritability of growth traits and meat productivity for boars of VCN03 sire line was in a greement
with most of publications of other authors (Gu et al., 1989; Tran Thi Minh Hoang et al., 2008a; Kiszlinger et
al., 2011; Saintilan et al., 2011. However, there were few reports (Szyndler-Nedza et al.,2010; Radovic et al.,
2013), in which heritability of ADG was lower (0.07 to 0.11).
One generation selection improved ADG, back fat thicness, loin muscle thickness, lean meat
percentage indicating that selection for these traits was very efficient and need to be focused more.
Chapter VI
CONCLUSION AND RECOMMENDAION
6.1.
Conclusion
Reproductive performance of sows of VCN03 sire line was low. Alive newborn number, weaned
number/litter and weaned weight/litter was 8.85 piglets; 8.15 piglets and 58.56 kg, respectively
20
Semen quality of boars of VCN03 sire line was good and met the temporary national standard for
exotic boars in AI programs issued by Ministry of Agriculture and Rural Development (Decision
N01712 QD-BNN, 2008).
While growth rate, lean meat percentage of boars of VCN03 line were high. back fat thickness of boars
of VCN03 sire line was low. ADG (g/day), estimated leen meat percentage and back fat thickness were
796.18 g/day; 60.37%, and 9.88 mm, respectively.
Heritability of most reproductive performance trait of sows of VCN03 sire line was low (0.10 to 0.19).
Heritability of weaned weight/litter trait was medium (0.24).
Heritability of growth and meat productivity traits of boars of VCN03 sire line was low or high
depending on studied traits. Whie heritability of both ADG and back fat thickness traits was only 0.34,
heritability of loin muscle thickness and and lean meat percentage was high (0.58 and 0.56). Reproductive
performance was strongly influenced by external factors therefore phenotype based selection was not
effective.
After one generation selection using EBV, ADG, loin muscle thickness, lean meat percentage of boars
of VCN03 sire line were increased by 60.09 g/day; 1.96mm; 1.4%, respectively. After one generation
selction using EBV, backfat thickness of boars of VCN03 sire line were decreased by 0.89 mm. These
progresses indicated that EBV based selection was very effective.
Use of REML method and MTDFREML software, 5% of sows with the highest EBV per each
selective traits (18 sows) and 1% of boars (9 boars) with the highest EBV for each selective trait were
selected for next selection programs. The above sows and boars were good source of genetic materials in the
nucleus herd for the genetic improvement of quality of herds of VCN03 sire line in Tamdiep pigs research
and development station.
6.2.
Recommendations
The population of pigs of VCN03 sire line needs to increase to avoid inbreeding and to make sure that
the selection and pure breeding would be done smoothly.
Establishing selective indexes using EBV for better improvement of performance and meat quality of
pigs of VCN03 sire line would be given a priority in selection programs.
Estimated breeding values needs to be used in selection work for improvement of productivity and
meat quality of VCN03 sire line and other pig lines in Vietnam.
Periodical importation of new genetic resources and introduction of new genetic materials into VCN03
sire line to avoid inbreeding and improve productivity and quality would be an important step.
Improvement of the external environment as such as feeding management, housing..to reduce any
negative influence would be paid more attention.