Waterfowl Husbandry in Our Country Is a Traditional Profession, Associated with Wet Rice

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INTRODUCTION

1. Urgency

Waterfowl husbandry in our country is a traditional profession, associated with wet rice agriculture.

This is an important livelihood for farmers, especially in the Mekong Delta.

In recent years, in order to meet the demand of production, our country has imported many duck breeds of the world, both directly producing the same breed and produce the genetic materials for hybridization to create strains, breeding, hybrid combinations which high yield suitable for different types of duck farming.

However, because the imported duck breedings are mainly grandparents and parents, they can not be kept for long time. On the other hand, the genetic advances of poultry breeding selection is constantly improving globally, lead to the quality imported breedings are easy to lag, unlessthe breeding supplement and selection are not carried to improve some performance criterias.

According to this trend, in the past time from imported materials, some domestic waterfowl breeding research and production establishments have applied the traditional breeding selective methods to select and hybrid the new strains, hybrid combinations which large release weight, shorter raising times and lower feed consumption for one unit of product.

These strains and hybrid combinations are suitable for different sizes and modes of livestock production in order to serve the immediate production needs. However, in terms of some important productivity criterias (such as muscle ratio, etc.) have not been researched.

In addition, these studies have only stopped in the simple selection methods, which are thecharacteristic selection or selection based on the phenotypic value, but not focused on the genotyping value as well as no researchon improving brisketrate of Super meatbreeding in our country.

Approaching trend of the world, Ducks Research Center of Dai Xuyen, Center of Research and Development of Poultry Breeding of Vigova, under National Resarch Institute of Animal Science have selected to create some strains of Super meatbreeding which have high rate of brisket.

In particular, the topic "Selection of two strains of Super meatbreeding to create commercial hybrid combinations which havehigh meat yield and breast muscle" was deployed atDucks Research Center of Dai Xuyen in that direction.

2. Objectives

- Seclection of TS132 drake strains at 7 weeks of age had body mass and high rate of brisket correspond to 3.25 kg/drake; 3.10 kg/duck and 17%.

- Seclection of TS142 duck strains with high rate of brisketand egg yields correspond to 212 eggs/duck/42 weeks and 17%.

- Creation of hybrid combinations two commercial strainswhich were developed to increase body mass and high rate of brisketat 3.1 to 3.2 kg/duck at 7 weeks of age and 17% respectively.

1. Scientific and practical significance

3.1. Scientific significance

- Apply multi-characteristic selection method and use selection index based on the estimated breeding value by BLUP to select waterfowl under the conditions of our country.

- The result of this research is the valuable reference for research and teaching at scientific and training institutions in our country.

2.2.Practical significance

- Seclection of two duck strains and commercial hybrid combinations which had bothbody mass and high rate of brisketto meet requirements of duck industry and farm. This has contributed to the restructuring strategy in poultry farming in our country.

- The result of article contributes to help local livestock establishments to actively produce high-yield ducks replacing the imported ones.

1. Novelty of article

- Produces new strains, hybrid combination with high meat yield and high rate of brisket.

-Apply the modern waterfowl breeding selective methods in conditions of our country.

5. Composition of thesis

Thesis includes: Introduction: 3 pages; Chapter 1. Overview: 51 pages; Chapter 2. Materials, contents and methods of research: 9 pages; Chapter 3. Results and discussion: 58 pages; Conclusion and recommendation: 2 pages; Table of Overview part: 18 tables; Table of Materials Research part: 4 tables; Table of Results and discussion part: 38 tables; Graph: 25; Reference materials: 96 (48 in Vietnamese, 48 in foreign languages); 14 annex pages, 11 illustration figures.

CHAPTER 1. OVERVIEW

As we know, the individual phenotypic value (P) is determined by the genotype value (G) and external error (E). While genotype value includes the cumulative genetic value (i.e. breeding value or A-value), error by gene interaction (D), epistasis (I), thus individual phenotypic value is shown:

P = G + E = A + D + I + E

In the above-affect component, only the effect of cumulative genetic is inherited for next generation so this component is of interest in selectivity.

Each individual in offspring generation is able to receive a haploid gamete (n) from each of their parents. In meiosis to create gamete, each gene (allene) in pairs of parental genes will be separated and transformed into a gamete and then the dominant interaction will be broken down.

Therefore, the dominant genetic effects by interaction of pairs of genes at the same site will not be inherited for next generation. At the same time, in the meiosis process, the recombination of genes will also disrupt interactions between genes at different gene sites, except in certain cases where genes are closely linked in genetic.

However, these gene links are very rare and have a negligible effect. The larger genetic value has, greater genetic coefficient gets andgreater potential of genetic ability lead to higher efficiency.

CHAPTER 2. MATERIALS, CONTENTS AND METHODS OF RESEARCH

2.1. Materials, location and time of research

- The SM3SH grandparents (T13 drake strains) and Star53 grandparents ducks (ST1 drake strains) are used as raw material to create drake strains.

- The SM3SH grandparents (T14 duck strains) and Star53 grandparents ducks (ST2 duck strains) are used as raw material to create drake strains.

2.2. Content

Content 1:Selection, creation of TS132 drake strains which increases body mass fast and high rate of brisket.

Content 2: Selection, creation of TS142 duck strains which has high rate of brisket and high egg yield.

Content 3:Evaluation of meat yield of commercial ducks were hybrided from two new strains.

2.3. Methods of research

2.3.1. Methods of research for content 1

*Cloning selection:Visual assessment to detect ducks with unqualified breed standards. Selection criterias are body mass and brisket’s thickness at 7 weeks of age. Selectivity-index-related selection based on estimated breeding value by MT-BLUP and economic coefficients, individuals with selectivity index from high to low will be selected from each family (drake’s value not less than Xtb+1σ, duck’s value not less than average value).

Selected index indices for drake strain:

Im = 0.037*EBV1 + 3.82*EBV2

2.3.2. Methods of research for content 2

* Cloning selection: Visual assessment to detect ducks with unqualified breed standards. Standard criterias is body mass at 7 weeks of age. Selectivity-index-related selection based on estimated breeding value by MT-BLUP and economic coefficients, individuals with selectivity index from high to low will be selected from each family.

Steady-state criteria isegg mass, all eggs which were created from the 38 to 41 week ducks, will be weighing, Xtb ± 1.5σ.

Phương trình chỉ số chọn lọc đối với dòng mái:

Selected index indices for duck strain:

If = 0.037*EBV1 + 3.82*EBV2 + 7.45*EBV3

Method of economic value determination

The economic value is determined based on the accounting method, accounting data of Duck Research Center of Dai Xuyen, the selling price of products in the North market.

Công thức tính giá trị kinh tế:

Formula for economic value:

Vi = Ri – Ci

Method of Genetic Analysis

Statistical model for analysis of body mass and brisket’s thickness characteristic of 7 week old drake strain:

Yijkl = µ + THi + GTj + ak + eijkl

Statistical model for analysis of body mass and brisket’s thickness characteristics of 7 week old and egg yield of 42 week old duck strain:

Yijk = µ + THi + aj + eijk

Methods of analysis foreffect of fixed factors to yield characteristic

Applying the General Linear Model (GLM) analyzes the fixed factors which affecting yield characteristic. Statistical Analysis Model:

Yijk = µ + THi+ GTj + eijk

Method of data collection

Ducks are numberedin wing at the first hatch and reservestage to trace genealogy in each generation; grafted into families in the individual housing system.

Each individual housing box contains 1 drake (1 reserved drake and outside) and 5 ducks (30% reserved duck and outside). Each generation will be grafted40 families.

Eggs for replacement for next generation are marked individually for each family, for each duck and each strain. Eggs are placed in individual bins. Data is collected by weighing andcounting. Body mass, egg weight is electronically balanced (accuracy ± 0.5g).

Brisket’s thickness was measured by RENCO ultrasound (US).

2.3.3. Methods of research for content 3

Diagram of commercial duck:

Strain ♂TS132x♀ TS132♂TS142x♀ TS142

Parents ♂ TS132 x ♀ TS142

Commercial duck TS34

Measurement method of brisket’s thickness:

Brisket’s thickness was measured by RENCO ultrasound (US).Measure at the location where head of sternumof middle chest is centered from top to bottom along duck body approximatly 2 cm and from split line of middle chest 1.5 cm to left chest. When measuring, hair will be removed at measuring site approximatly2 x 2 cm, apply gel on skin surface and place an ultrasonic probe perpendicular to skin surface, then press button to display result.

Number of ducks used in research:

Table 2.1. Number of ducks used in selectivity populationover 4 generations

Gen / Criteria / TS132 / TS142
Drake / Duck / Drake / Duck
Gen 1 / Number of 1 day old individual (unit) / 542 / 507 / 416 / 463
Number of 7 week old individual (unit) / 528 / 494 / 404 / 450
Number of reproductive performance test (unit) / 40 / 200 / 40 / 199
Number of used as breeding for next generation (unit) / 24 / 65 / 33 / 127
Gen 2 / Number of 1 day old individual (unit) / 354 / 500 / 450 / 550
Number of 7 week old individual (unit) / 347 / 488 / 418 / 530
Number of reproductive performance test (unit) / 40 / 200 / 40 / 199
Number of used as breeding for next generation (unit) / 26 / 65 / 35 / 133
Gen 3 / Number of 1 day old individual (unit) / 350 / 500 / 374 / 576
Number of 7 week old individual (unit) / 342 / 482 / 364 / 567
Number of reproductive performance test (unit) / 40 / 200 / 40 / 199
Number of used as breeding for next generation (unit) / 37 / 101 / 32 / 117
Gen4 / Number of 1 day old individual (unit) / 347 / 503 / 405 / 546
Number of 7 week old individual (unit) / 343 / 497 / 396 / 532
Number of reproductive performance test (unit) / 40 / 208 / 40 / 208
Number of used as breeding for next generation (unit) / 31 / 108 / 35 / 121

Table 2.2. Number of ducks for grown survey and operated through 4 generations

Gen / Surveyed herd / Controlled herd / Operated duck
Drake / Duck / Drake / Duck / Drake / Duck
Gen1 / 120 / 120 / 120 / 120 / 10 / 10
Gen2 / 120 / 120 / 120 / 120 / 10 / 10
Gen3 / 120 / 120 / 120 / 120 / 10 / 10
Gen4 / 120 / 120 / 120 / 120 / 10 / 10

Table 2.3. Number of ducks for reproduce survey through generations

Gen / Surveyed herd / Controlled herd
Drake / Duck / Drake / Duck
Gen1 / 50 / 200 / 50 / 200
Gen2 / 50 / 200 / 50 / 200
Gen3 / 50 / 200 / 50 / 200
Gen4 / 50 / 200 / 50 / 200

Table 2.4. Number of hybrid combination of 2 strains and controlled herd of 4th generation

Gen / (TS34)
Hybrid combination of 2 strains / Controlled herd
Drake / Duck / Drake / Duck
4 / 180 / 180 / 180 / 180

Method of Data Processing

Statistical processing software such as EXCEL, SAS 9.1. Estimation of breeding value using PEST software, version 4.2.3 (Eildert Groeneveld, 1993), estimation of parameters by VCE6 software (Milena Kovac and Eildert Groeneveld, 2003), frequency plotting using Minitab 18.1.10.

The results of the three statistical parameters were presented as sample size (n), mean value (SD) and standard deviation (SD), use max. 2 decimal places (depending on the trait, calculate body mass = grams, one decimal).

Comparative testing of mean values of standard deviations using t-test, percent values used Chi-squared percentages.

CHAPTER 3. RESULTS AND DISCUSSION

3.1.Result of selection, creation of TS132 drake strains

3.1.1.Effects of some factors on body mass and brisket’s thickness characteristic of 7 week old drake

Age and gender factors significantly affected on body mass and brisket’s thickness characteristic of 7 weekold drake (P <0.01).

3.1.2. Changes in the components of variance and genetic coefficientovers generations

For body mass characteristic, this change ranged from 3.6% to 19.4%, and 8.0% to 30.0% for brisket’s thickness characteristic. This indicates the stability of the genetic parameters of characteristic.

3.1.3. Covariancebetween body mass and brisket’s thickness characteristic

Characteristicof body mass and brisket’s thickness of 7weekold drake have popositive genetic covariance, in genetically, two characteristicare trend of change together, positive phenotypic covariance shown that in terms of phenotypes, these characteristic also have the same trend of variability and depending on level,

however, the external covariance is negative, therefore in terms of externality, for some reason this pair of characteristic is reversed trend, but in term of absolute external covariance is much smaller than genetic covariance and phenotypic covariance,

this explains that for effect of external conditions that make this characteristic to rise result inother characteristic is reduced or may increase but not significantly.

3.1.4. Genetic coefficientand correlation between body mass traits and 7-week-old breast thickness

Genetic coefficient of body mass characteristic at 7 week oldwas 0.53 with error of 0.04 and the genetic coefficient for brisket’s thickness characteristic at 7 week old was 0.81 with error of 0.02. These are quite small errors.

For drake: correlation coefficient (r) of phenotype between body mass and brisket’s thickness was 0.72 (statistically significant with P <0.05), correlation coefficient of phenotype between muscle body mass and brisket rate was0.62 (not statistically significant with P> 0.05). This is quite reasonable as it explains that not large drakewill have high brisket rate,

Correlation coefficient between brisket’s thickness and brisket rate was 0.87 (statistically significant at P <0.05). The regression equation of brisket rateand brisket’s thickness at 7weekold drake was statistically significant at P <0.05 with coefficient of determination of 0.81 (modified coefficient of determination was 0.79).

For ducks: correlation coefficient (r) of phenotype between body mass and brisket’s thickness was 0.66 (statistically significant with P <0.05), correlation coefficient of phenotype between muscle body mass and brisket rate was 0.67 (statistically significant with P <0.05),correlation coefficient between brisket’s thickness and brisket rate was 0.90 (statistically significant at P <0.05). The regression equation of brisket rateand brisket’s thickness at 7weekold drake was statistically significant at P <0.05 with coefficient of determination of 0.76 (modified coefficient of determination was 0.73).

Thus, correlation coefficient of phenotype between brisket rate and brisket’s thickness characteristic 7weekold drake wasin very tight level of 0.87-0.90. This helps selection of brisket rate through selection of brisket’s thickness is effective.

3.1.5.Expected selection rate, Selection differential, and effective for characteristic

Selection differentialof body mass characteristic was from 201.43 to 343.54 g for drake, and from 103.76 to 193.29 g for ducks; Selection differentialof brisket’sthickness characteristics was from 0.65 - 1.34 mm for drake, 0.67 - 1.65 mm for ducks. Selection differentialin both body mass and brisket’s thickness characteristics decrease through selective generations. This may be due to the selective effect of decreasing selection differentialover generations.

This result is consistent with increase in estimated breedingvalue through selective generations.

The results from the pre-selection and post-selection herds show that absolute of skewness parameter of post-selection herds is significantly smaller than that of pre-selection herds. This shows that the standard distribution of post-selection herds has increased.

The absolute of kurtosis parameters of post-selection herds is significantly smaller than that of pre-selection herds (except for first generation drake with higher kurtosis parameters of post-selection than those of pre-selection). This shows the level of scattering of body mass data.

3.1.6. Genetic trends and genetic advancement of selective traits

3.1.6.1. Breeding value and phenotype value of body mass characteristic of 7 week old drake

The results of the estimated breeding value of body mass characteristic shown that breeding value increases over each generation, and genetic trend increases with each generation in both drake and duck, the difference between generations is quite high as shown by increasing of breeding value through each generation. For selection herd was fed with free-time feeds at day, with the increase in breeding value, phenotypic value of characteristic also tended to increase, although the difference was not clear.

The genetic improvement of characteristic is markedly improved by the positive regression coefficient. Body mass has a genetic improvement of 70.37 g/generation for drake and 74.95 g/generation for ducks (value for both was 72.76 g/generation). The regression coefficient of characteristic was quite high with R2 = 0.97 for body mass with P <0.001.

3.1.6.2. Breeding values and phenotypic value of brisket’s thickness characteristic of 7 week old drake

As breeding value, phenotypic value of the body mass characteristic increased over each generation, breeding value and phenotypic value of brisket’s thickness characteristic increased over each generation.

This genetic gain is increased through each generation through a regression coefficient that is positive and reaches 0.47 mm/generation for drake and 0.48 mm/generation for duck (calculated for both was 0.47 mm/generation) with a coefficient of 0.94 (P <0.001). Thus, direct selectivity of this characteristic is lower than the expected selectivity of 51.78%.

3.1.7. Inbreeding coefficient of TS132 ducks over selective generations

The inbreeding coefficient shows that: generation 1 has not occurred inbreeding. Inbreeding was found out from generation 2 onwards. The highest inbreeding rate in the 4th generation was 88.57%, which is consistent with the higher number of generations, the more common ancestry, selective rate of drake is ranged from 5 to 10%, ducks from 15 to 25%, the next-generation mating in the next generation is very likely to occur.

The highest inbreeding coefficient in the 4th generation was 0.032 with the highest inbreeding coefficient of 0.25 (i.e., in the previous generation of half-brothers or mothers-in-law) The inbreeding coefficient is 0.25. Inbreeding coefficient increased over time with increase in number of inbreeding individuals, to 4th generation, highest value was 0.032 with highest inbreeding coefficient of 0.25.

3.1.8. Survey of growth and yield of TS132 super meat duck

3.1.8.1.Body mass of surveyed herd and controlled herd of 7 week old duck which free-time feeds at day

It can be seen that in 4th generations there was a statistically significant difference (P <0.05) between surveyed herd and controlled herd, while generation 1 of 7 week old duck in surveyed herd,body masswas 3110.2 g for drake, 2950.4 g for duck,and controlled herd were 3049.1 g for drake and 2895.9 g for duck respectively. Thus, generation 1 is higher, was 61.1 gfor drake and 54.5 g in duck, both was 60.2 g in comparison to controlled herd. By 4th generation there was a noticeable difference, 7-week-old body mass of surveyed herd was 3336.7 g for drake and 3150.7 g for duck, which higher than controlled herd which was 281.2 g for drake and 239.3 g for duck, both was 260.4 g.