Dang Vu Binh and Ngu;yen Van Thang

1. INTRODUCTION

Swine prodùction'plays an important foIe in the agricultural economy of Vietnam.Pig meat accounts for nearly 80% of the total animal meat, mainly for domesticcqnsumption and importantlyfor export as weIl.

ln the North of Vietnam, indigenous sows make up a high proportion in the totalsow herd, including primarily Mong Cai sows, while crossbred and exotic sows tend tobe increased in numbers.

Exotic boars, mainly of Yorkshire and Laridrace breeds, are used in almost aIlcrossing formulae with Mong Cai or FI sows (Yorkshire or Landrace sire x Mong Caidam) to produce commercial pigs. However, the growth rate and feed conversioneffic.iency are still rathér l°v.:r;...especially, the low leanness of the carcass does not meetthe requirements of ~h'f:,inteinational and domestic markets. .

The Belgium" Pietrain is a swine breed famous for high meat productivity and

especially high meat quality. The stress-resistant Pietrain ReHalline of Liege University,which cao give 60% le.an meat when slaughtered at 114 kg, bas been inti"oduced intoVietnam. The use of Pieti"ain boars in crossing programs bas been an important way toproduce commercial pigs with high lean percentages in many countries. As for Vietnam,this is new and necessary. Therefore, we have conducted initial studies on reproductive

perfomances of different types of sows bred with Pieti"ain boars to produce crossbredpigs with high productivity in the North of Vietnam.

The studies were aimed at:

-Evaluating the use of semen after ti"ansport from a long distance.

-Evaluating reproductive performances of several types of sows bred withPieti"ain boars.

2. MATERIALSAND METHODS

2.1. Studied animais andbreeding schemes

Pietrain boars were used tqbreed with MongCai sows, FI sows (yorkshire x MongCai), and yorkshire sows.~tîien of Pietrain boars was transported from Binh ThangResearch and Development Centèr (the Agricultural Research Institute of SouthemVietnam) to be artificially inseininated (AI) to the different types of sows in the North.

2.2. Study time and site

The present studies were carrie~ out "during the period of 2000-2002 in farmerhouseholds in Hanoi, Hung Yen and at the Northern Swine Breeding Company.

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2.3. Study parameters.-Conception rate

Conception rate = (No of pregnant sows[fotal,sows inseminated) x 100-Litter size: Total piglets bom, including both alive and dead ones.-Number bom alive/litter: Number of piglets bom and alive until completion

of parturition.-Number kept for rearing/litter: Number of piglets kept forrearing (discardingtoo small ones). .

-Number of 21 day-old piglets/litter: Number of piglets alive at 21 days of age,-Number of weaned pigs/litter: Number of piglets alive until weaning.-Birth weight/litter (kg).-Birth weight/head (kg).-Weight/litter at 21 days of age (kg).-Weight/h~ad at 21 days of age (kg).

-Weight/litter atweaning (kg).-Weight/head atweaning (kg).-Weight/litter at 60 days of age (kg).-Weight/head at 60 days of age (kg).-Weaning time (days)

2.4. Study Methods

a. Obsel-vation ofthose sows inseminatedwith Pietl-ain semen to calcLdate the conception rate.

b. Obsel-vation of reprodLlctive peiformances of th ose sows inseminated with Pietl'ain semen:

,- Counting piglets al: birth, selection for rearing, 21 days of age, weaning and 60days of age.- Weighing the piglets with a balance of 0.1. kg accuracy.

3. RESUlTS

3.1. Results of lnsemination

Semen dosages of Pietrain boars were transported 7 limes from Binh. ThangResearch and Development Center (the Agricultural Research lnstitute of SouthemVietnam) to the North by plane and then by motorbike to be artificially inseminated tothe different types of sows. Results are presented in Table 1.

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The semen had been collected în the' early morning, stored in plastic bottles put iniced boxes and transported by air from Tan Son Nhat airport to Noi Bai airport, then bymotorbike over an average distance of 60km from Noi Bai to the sites ofinsemination. The semen was'used for AI in the following clay or morning. ln spiteof that, the conception rate (CR) was fairly high. The CR was highest (67.67%) forbatch 5 and lowest for batch 2 and batch 6 (60.00%). The average CR for aIl 7batches was 64.22%.

32. Reproductive performances c;>f sows inseminated with Pietrain semen

3.2.1. Reproductive performances of Mong Cai sows

Reproductive performances of Mong Cai sows inseminated with Pietrain semen arepresented in Table 2.

Table 2: Reproductive performances of M ong Cai sows inseminatedwith Pietrain semen

Trait Unit

head-head

head

head

head

kg

kg

kg-~

kg

kg

days

%, %

X:!:ffix

10.92:1: 0.78

Cv (DIa)

23.84

24.91

LIfter size

N. barn olive/lifter

9.54:!: 0.31

9.31 :1: 0.41

9.15:1:0.47

0.80:1: 0.02

8.38:1: 0.71

3.77 :1: 0.07 ,

35.16:1:2.14

10.98:1: 0..22

99.41 :!: 6.80

60iC'

91.02

95.18

11.80

16.04

18.84~

3Q:S63.;l!!i

22,03

22.44

'24.66

N. weaned pigs/litter

Birth weight/head

n

13

13.

13

13

13

135I-I 1311211

r 13

118

13

118

135

118

Birth weight/litter -Weight!head àt 21 days of age

Weighf/litter of 21 dciys of oge

Weighf/heod of weoning

$X

2.84

2.70

1.12

1.49

1.72

0.23

2.56

0.82

7..73--" ,.-2.46

24.52

As can bè seen trom Table 2, Mong Cai sows bred with Pietrain semen had a litt~rsize of lO.92:t0.78 heads with 9.54:t0.31 piglets kept for rearing/litter and 9.15:t0.47wearied pigs/litter. The ;:lverage birth weight was 0.80:t0;02 kg/head and 8.38:t0.71kg/litter. The average weight at 21 days of age was 3.77:t0.07 kg/head and 35.16:t2.14kg/litter. The average weight at weaning was 10.98:tO.22 kg/head and 99.41:t6.80kg/litter with a weaning time of 60 days. The"survival rate at birth and at weaning was91.02% and ~5.18%, respectively.

3.2.2. Reproductive performances of ~ l(Y x MC) sows ..'

Reproductive performances of F\(YxMC) sows inseminated with Pietrain semen. arypresented in Table 3. '

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Table 3: Reproductive performances of FI (Y xMC) sows inseminatedwith Pietrain semen

Trait X:t:m.Unit

head

head

head

head

head

kg-kg

kg

kg

kg

kg

kg

kg

days%

%

Cv (%)

30.32

29.45

19.56

33.91

39.12

24.47

29.32

19.06

38.33

20.06

42.34

33.91

51.41

lifter sile

N. barn olive/lifter

11.28:t J.53

11.00;!: 1.45

10.60:t 0.92

10.00 :t 1.51

9.80:1:1.71

1.20 :t 0.04

12.90:1: 1.69

4.75:1:0.12

48.28 :1: 8.27

6.38 :1: 0.17

63.66:1: 12.05

13.47:1: 0.62

121.37:1: 27.90

30

97.51

92.45

N. kept for rearing/litter

N. 21 day-old piglets/litter

N. weaned pigs/litter

Birth weight/head

Birth weight/litter

Weighf/heod of 21 doys of oge

Weighf/litter of 21 doys of oge

n

5

5

5

5

5

54

5

50

5

49

5

49

5

49

54

49

$X

3.42

3.24

2.07

3.39

3.83

0.29

3.78

0.90

18.50

1.28

26..95

4.56

62.39

Weighf/heod of weoning

Weighf/litter of weoning

Weighf/heod of 60 doys of oge

Weighf/litter of 60 doys of oge

Weaning time

SuNivol rote ot blrth

SuNivol rote ot weoning

Table 3 shows that FI sows bred with Pietrain semen had a lifter size of II.28::1:1..53heads with 10.6::1:0.92 piglets kept for rearing/litter and 9.80::1:1.71 weaned pigs/litter.The average birth weight was 1.20::1:0.04 kg/head and 12.90::1:1.69 kg/litter. The average

weight at 21 days of age was 4.75::1:0.12 kg/head and 48.28::1:8:27 kg/litter. The average

weight at weaning was 6.38::1:0.17 kg/head and 63.66::1:12.05 kg/litter with a weaningtime of 30 days. The average weight at 60 days of age was 13.47::1:0.62 kg/head and

121.37::1:27.90 kg/litter. The survival rate at birth and at weaning was 97.51% and

92.45%, respectively.

3.2.3. Reproductive performances of Yorkshire sows

Reproductive performances of Yorkshire sows inseminated with Pietrain ~emen arepresented in Table 4.

It is shown in Table 4 that that Yorkshire sows bred with Pietrain semen had a lifter

size of Il.60::1:0.85 heads with 9.90::1:0.58 piglets kept for rearing/litter and 9.70::1:0.55

weaned pigs/litter. The average birth weight was 1.35::1:0.02 kg/head and 13.96::1:0.76

kg/iitter. The average weight at 21 days of âge was 5.67::1:0.09 kg/head and 56.12::1:3.48kg/litter. The average weight at weaning was 7.39::1:0.13 kg/head and 71.27::1:4.76

kg/litter with a weaning time of 28 days. The average weight at 60 days of age was

21.07::1:0.29 kg/head and 202.23::1:12.88 kg/litter. The survival rate at birth and at

weaning was 91.38% and 97.98%. respectively.

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Table 4: Reproductive performance,s: of Yorkshire sows inseminatedwith Pietrain semen

Trait -X:l:m-x

11.60 :1: 0.85

.10.60:1:0.77

9.90:1:0.58

9.70:1:0.55

9.70:1: 0.55

1.35 :1: 0,02

13.96:1: 0.76

5,67 :1: 0.09

56.12:1:3.48

7.39 :1: 0.13

71.27:1:4.76

21.07:1: 0.29

202.23:1: 12.88

28

91.38

97.98'

Unit

head.headheadheadhead

kg

kg~

kg

kg.

kg

kg

kg

kg

days%

%

Cv (%)

23.41

23.19

18.71

18;21

18.21

13.68

17.40

17.36

19.64

18.16

21.15-

13.18

20.14

Lltter size

N. barn olive/lifter

N. kept for rearing/litter

N. 21 day-old pigletsjlitter

N. Weaned pigsjlitter

Birth weight/head

n10

]0

10

10

10

103

10

99

10

97

10

95

10

97

103

97

Birth weight/litter

Weighf/heod of 21 doys of oge

Weight/litter ot 21 doys of oge

L2.71

2.45

1.85

1.76

1.760.18

2.43

0:98

11.02

1.34

15.07

2.91

40.74

Weight/heod ot weoningWeighf/litter of weoning

Weight/head at 60 days of age~-

Weightjlitter ot 60 dots of oge

Weaning time

Survivol rate ot birth

Survivol rate ot weaning

Comparisons on reproductive performances were made among the different types ofsows inseminated with Pietrain semen. Results are given in Table 5.

Table 5: Differences in reproductive performances among the different types of sowsinseminated with Pietrain semen

son Trait PxMC(l)ab

P x(YxMC) (2)

abc

a.b

cb ...b ..b ...b.b ...

a..

Px Y (3)

abc

a,

bc ,c'. .b ...c'. .b ...,c'. .b ...

Lifter sile

N. barn olive/lifter23

4

5

6

7

8

9

N. kept for rearing/litter c

N. 21 day-old piglets/litter

N. weaned pigsjlitter

~699ay-old

pigs/litterBirth weight/head

ab

c

a...aa...a

a...

Birth weight/litter

Weighf/heod of 21 doys of oge

10

11

Weight/litter at.21 days of age

Weight/head at 60 days of age

12 Weight/litte~~at ~O_9~ays~age aN.R: Different letters on the same row in the last three columns show significant

differences in the values of the trait at the following statisticalleve's:*: P < 0.05.**: P <0.01.***: P < 0.001.

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It can be' seen from Table 5 that the reproductive traits such as litter size, number ofpiglets born ,alive peT litter, number of piglets/litter at 21 days of age, number ofweaned.pigs/litter and number of pigs/litter. at 60 days of age were not significantlydifferent between the different crossing forrnulae (P>0.05). The average birthweight/heâd was significantly different between the crossing forrnulae (P<O.OOI). Theaverage birth weight/litter was different at P<O.OI between forrnulae 1 and 2, and atP<O.OOI between forrnulae 1 and 3, there was no significant difference betweenforrnulae 2 and 3 (P>0.05). The difference in the average weight/head at 21 days of agewas significant at P<0.Q5 between fonnulae 1 and 2, and at P<O.OOI between forrnulae1 and 3, but non-significant between forrnulae 2 and 3 (P>0.05). The averageweight/head at 60 days of age was significantly different between aIl forrnulae. Theaverage weight/litterat 60 daysofage was not significantly differentbetween forrnulae1 and 2 (P>0.05), but significantly different at P<O.OOI between forrnulae 1 and 3, andat P<O.OI between forrnulae 2 and 3.

4. CONCLUSIONS, SHORTCOMINGS AND RECOMMENDATIONS

4.1. Conclusions

-Use of semen of Pietrain boars from the South for AI of the different types ofsows resulted in an average conception rate of 64.22%.

-Mong Cai sows bredwith Pietrain boars had an average litter size of 10.92:t0.78heads with 9.54:t0:31 piglets kept for rearing/litter and, 9,15:t0.47 weaned pigs/litter.The average birth weight was 0.80:t0.02kg/head and 8.38:t0.71 kg/litter. The averageweight at 21 days of age was 3.77:t0.07 kg/head and 35.16:t2.14 kg/litter. The averageweight at weaning was 10.98:t0.22 kg/head and. 99.41:t6.80 kg/litter with a weaningtime of 60 days. The survival rate at birth and at weaning was 91.02% and 95.18%,

respectively.-FI (YxMC) sows bred with Pietrain boars had an ,average litter size of 11.28:1::1.53

heads with 10.6:1::0.92'piglets kept for rearing/litter and 9.80:1::1.71 weaned pigs/litter.The average birth weightwas 1.20:1::0.04 kg/head and 12.90:1::1.69 kg/litter. The averageweight at 21 days of age was 4.75:1::0.12 kg/head and 48.28:1::8:27 kg/litter. The averageweight at weaning was 6.38:1::0.17 kg/head and 63.66:1::12.05 kg/litter with a weaningtime of 30 days. The average weight at 60 days of age was 13.47:1::0.62 kg/nead and

121.37:1::27.90 kg/litter. The survival rate at birth and. at weaning was 97.51% and

92.45%,.respectively..-Yorkshire sows bred with Pietrain boars had an average litter size of Il.,60:l:0~85

heads with 9.90:1:0.58 piglets kept for rearin~/litter and 9.70:1:0.55 weaned pigs/litter.'The average birth weight was 1.35:1:0.02 kg/head and 13.96:t0.76 kg/litter. Thé averageweight at 21 days of age was 5.67:1:0.09 kg/head and 56.12:1:3.48 kg/litter. The averageweight at Vfeaning was J.39:t0.13 kg/head and 71.27:1:4.76 kg/litter with a weaning

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time of 28 days. The average weight at 60 days pf age was 21.07 :t 0.29 kg/head and202.23:t12.88 kg/litter, The survival rate at birth and at weaning w~s.91.38% and97 .98%, r~spectively.

-The different types of sows bred' with Pietrain boars had similar litter sizes,numbers of piglets born' alive peT litter, numbers of piglets/litter at 21 days of age,numbers of weaned pigs/litter and numbers of pigs/litter at 60 days of age. The averagebirth weights peT head and peT litter were significantly different between the crossingformulae.

4.2. Shortcomings and Recommendations

-Shortcomings: It was faced with,difficultiestransporting semen from ,too long adistance. Consequently, the number of sampl.es observed was limited.

-Recommendations: Studies with largè scales should follow to gain more accurateconclusions. .

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