Abstract

ABSTRACT

“Effects of temperature, relative humidity on growth performance, diarrhea disease in the ross 308 chicken and antibiotic sensitivity test for isolated diarrheal bateria”

NGUYỄN THỊ THANH GIANG

The study was conducted from 02/2009 to 02/2010 in Trang Bom district, Đong Nai province. The objectives of the study were to (i) survey productivity, (ii) isolate pathogenes causing diarrheal disease, (iii) analyze correlation of temperature and humidity on growth performance and ratio of diarrheal disease, and (iv) have an antibiotic sensitivity test for treating diarrheal disease. The study was, therefore, allocated in a completely randomized design with three replications in three different farms. Results were recorded as follows:

There was high fluctuation of housing temperature in week 1 (32.14-33.35°C), week 2 (29.21-30.14°C), week 3 (27.44-28.60°C), week 4 (26,81-27.04°C), week 5 (25.59-26.29°C), and week 6 (25.84-26.74°C) compared with the standard recommendation.

Housing humidity in week 1 (74,10-77,01%), week 2 (73,54-77,4%), week 3 (76,5-82,36%), week 4 (81,39- 83,87%) , week 5 (82,34-83,02%) , and week 6 (81,53-84,4%) was always higher than humidity of the standard recommendation.

The difference of temperature and initial weight directly affect the health or weight-gain, feed-intake and feed-conversion-ratio in the different stages of age. For example, slaughter weight reduced 20.5-25.3% (1,980-2,109.23g), feed-intake decreased 21.84-24.91% (3,654.70-3,804.24 g) while feed-conversion-ratio increased 1.14-11.37% (1.78 to 1.96). Temperature and humidity higher than the standard recommendation will directly or indirectly affect ratio of diarrheal disease (32.5-37.8%), ratio of respiratory disease (22.4-40%) and death ratio (4.45 to 7.84%) in chickens. In gerenal, diarrheal disease was caused by infection of E. coli (74-87%). The highest infectious ratio was found within 0-2 weeks of age (87%), gradualy decreased within 2-4 weeks old (74%) and then reincreased within 4-6 weeks of age (81%). Therefore, linear relationship of temperature or humidity with weight-gain, feed-intake, or ratio of diarrheal and respiratory disease was also found significantly (P<0,05).

Successful antibiotics in treating E.coli were Ceftriaxone (97.73%), Cefotaxime (95.45%), Colistin (93.18%), Amoxicillin/ Clavulanic acid (81.82%) and Cephalexin (72.73%). Additionally, E.coli can resist some antibiotics as Tetracycline (100%), Tobramycin, and Bactrim (90.91%), doxycycline (79.55%), Norfloxacin (70.45%) and Gentamycine (59.09%).

In summary, temperature and humidity may affect productivity and health of experimental herd. Thus, two these factors must be carrefully controlled to ensure their stability during production period in further efforts to improve production efficiency of the Ross 308 chicken.

Key words: temperature, humidity, growth performance, ratio of diarrheal and respiratory disease, mortality, correlation, antibiotic sensitivity test.

ABSTRACT

“Effects of H-FABP and RyR1 genotypes on blood characteristics, growth performance and meat quality traits in pig”

NGUYỄN HUY TƯỞNG

Objectives of the study were to analyze effects of H-FABP and RyR1 polymorphic sites on blood characteristics, growth performance and meat quality traits in Yorkshire x Landrace pigs raised at the Hoa An Experimental Animal Unit. Therefore, a total of 133 castrated males (30-100 kg LW) were used in the study for evaluating the economic traits. Physiological and biochemical blood parameters were tested at 30, 60 and 100 kg. The pigs were slaughtered at around 100 kg of live weight to measure percentage of carcass parts as well as pH values, driploss (DL), meat color (CL) at 6 time points (45 min, 6 hrs, 12 hrs, 24 hrs and 48 hrs after slaughtering). In addition, single nucleotide polymorphisms (SNPs) of the candidate genes H-FABP and RyR1 were identified using PCR-RFLP method. Results indicated that (i) red blood cell RBC (p>0,05) and white blood cell WBC (p<0,01) gradually decreased with age whereas platelets PLT₃₀ (289,06x10⁹/l) was higher than either PLT₆₀ (204,36x10⁹/l) or PLT₁₀₀ (219,97x10⁹/l) (p<0,01). Hematorite HCT, urea and glucose were stable during the experiment, (ii) growth gain (73.1 kg/head), daily gain (0.72 kg/head/day), relative growth rate (224,73 %) were slightly low while feed conversion ratio FCR (3,20) was higher than breed standards, (iii) dressing percentage (80,59%) and carcass percent (74.08%) were slightly lower whereas backfat thickness (~2,68 cm) was higher than standards; chemical compositions of ham and loin were stable. Additionally, pH, DL and CL of ham and loin gradually reduced after slaughtering. Ham quality was normal while loin was light color, soft and exudative (closely PSE). With score of 3 for color, both ham and loin showed the best pH and DL until 48 hrs after slaughtering and storing at 4^oC (iv) at position 1489C>T/MspI (intron 2) in H-FABP, the frequency of CC (75.75%) was higher than that of CT (24.24%). None of individual showed TT genotype. Also in this gene, genotypic frequencies of CG and GG were 27,27% and 72,73% respectively at SNP 1811C>G/HaeIII (intron 2). Further more, in RyR1 gene, genotype CT was 100% at nucleotide 1811C®G/Hin6I. In general, genotypic and allelic frequency of the genes fitted to Hardy-Weinberg equilibrium, and (v) 1489C>T/MspI (H-FABP) polymorphic association with HCT₆₀, PLT₁₀₀, Urea₆₀, BUN₆₀, loin dry matter, loin crude protein, loin water-holding capacity was statistically significant (p<0.05). Animals with CC genotype showed these traits better than ones with CT. Previous studies provided valuable information for definitive role of H-FABP in intramuscular fat, backfat thickness. Here, further evidences for association of the gene with many other traits are added. Therefore, H-FABP may be considered as a good candidate gene for animal breeding programs

Key words: pig, blood characteristics, growth performance, meat quality, H-FAPB and RyR1 gene, polymorphic association

ABSTRACT

“Effects of tumeric (Curcuma longa) and garlic on growth performance feed conversion and blood fat components of growing and finishing pigs”

ĐẶNG THỊ NGỌC HÂN

The study aimed at determining the effects of garlic and/or turmeric on growth performance and physiochemical blood characteristics of growing-finishing castrated-male pigs of the Yorkshire x Landrace breed group (30-100 kg of live weight). The study consisted of two experiments (i) twelve animals were allotted in a completely randomized design with three treatments and four replications. The control treatment (ĐC) was a basal diet, whereas the first and second contained the basal plus 0.1% dry-garlic powder (TK) and the basal plus 0.1% fresh-ground garlic (TT). It indicated that the supplementation of both dry and fresh garlic to the diet did not cause any effects on daily gain, feed-intake, feed conversion ratio and blood parameters except the total cholesterol and LDL-C contents significantly reducing from 2.09 mmol/L (ĐC1) to 0.92 (TK) and from 1.71 mmol/L (ĐC) to 0.31 mmol/L (TK) (P<0.01), respectively; and (ii) in another completely randomized design with five treatments and four replications, other castrates received the basal diet as the control (ĐC), the basal plus 0.05% dry-turmeric powder as the treatment 1 (N_0.05), the basal plus 0.1% dry-turmeric powder as the treatment 2 (N_0.01), the basal plus 0.05% dry-turmeric powder and 0.05% dry-garlic powder as the treatment 3 (NT_0.05), and the basal plus 0.1% dry-turmeric powder and 0.1% dry-garlic powder as the treatment 4 (NT_0.1). Similar to the first experiment, the supplementation of garlic and turmeric did not affect the observed traits for performance and blood characteristics. However, cholesterol (0.85 mmol/L vs 2.09 mmol/L) and LDL-C (0.45 mmol/L vs 1.71 mmol/L) concentration in NT_0.1 was lower than in ĐC significantly (P<0.01). Thus, garlic and turmeric may be used as feed additives with regard to reducing total cholesterol and LDL-C parameters in pigs.

Key words: pigs, garlic, turmeric, daily gain, feed-intake, feed conversion ratio, physiochemical blood characteristics

ABSTRACT

“Contribution of polymorphisms of the porcine Leukemia-Inhibitory-Factor and Myogenin genes to blood characteristics, growth performance and meat quality traits”

LƯƠNG THỊ NHUẬN HẢO

The current study aimed at analyzing polymorphic association of the MyoG and LIF candidate genes with physicochemical parameters of blood, growth performance and pork quality traits. Thus, (i) blood properties were determined using a Cell-DYN 1700 Hematology Analyzer and TC-3300; (ii) growth characteristics were, subsequently, administered during the growing (30 to 60 kg of body weight) and finishing (60 to 100 kg BW) periods; (iii) carcass traits were evaluated at a slaughter weight of approximately 100 kg according to the STAMEQ; (iv) chemical compositions of ham and longissimus dorsi muscle were analyzed followed the AOAC’s protocol and (v) genotypes of two candidate genes MyoG (3’-UTR, MspI) and LIF (exon 3, DraIII) were detected using PCR-RFLP technique. The study was conducted in 133 castrated male pigs of Yorkshire x Landrace crossbred raised at the Experimental Animal Unit of Can Tho University. Analyses revealed that (i) genotypic frequencies AA, AB and BB at MyoG locus were 9.10%, 45.45% and 45.45%, while those at LIF locus were 15.63, 71.87% and 12.50%, respectively; (ii) significant associations of MyoG genotypes with WBC_30,100 and HCT₁₀₀ of blood, ash and phosphorus of loin, pH₆₀ of loin, color of ham, and pressing carcass were found (p<0.05); (iii) genotypes of LIF were significantly associated with HCT_{30, 100}, PLT_60,100, RBC₁₀₀, urea₆₀/BUN₆₀, carcass length, fat of ham, pH_{45’, 36hrs, 60hrs} of loin, pH₄₅ of ham, color of loin and ham as well as driploss of loin (p<0.05). It was additionally indicated that the “B” allele at both loci played an important role in controlling some meat traits, in which heterozygous pigs were superior to homozygous ones. Results implied that SNP-based makers of MyoG and LIF can be designed for selection and breeding programmes owing to their values related to meat quality traits, glycolysis process and metabolism in pigs.

Key words: MyoG, LIF, polymorphism, meat quality traits, growth parameters, physiochemical properties, association.

ABSTRACT

“Prevalence of H5N1 Virus and Immune Response for Avian Influenza Vaccine in Ducks in Dong Thap”

PHAN MỘNG THU

Objectives of the study were to evaluate infectious rate of H5N1 virus and to determine immune response at 21 days post-inoculated with an inactivated H5N1 Reassortant Avian Influenza vaccine in ducks. Therefore, samples of serum and swab were collected and analyzed using the HI (hemagglutination inhibition) test and rRT-PCR, respectively.

Testing a total of 6,442 collected serum samples from vaccinated ducks resulted in high protective rates of flocks (84.76%) and samples (82.72%). There was a significant difference for the protective rates among districts in Dong Thap (p<0.05). In addition, geometric mean titer (GMT) value was 23.75. Significant difference (p<0.05) was found between (i) layer-ducks (88.56%) and broiler-ducks (73.32%), (ii) the raising model of biosafety (94,64%) and scavenging (81.20%) or semi-scavenging one (86.01%).

Analyzing serum samples from unvaccinated ducks (n = 3660) and muscovy (n = 2,677) indicated that the seroprevalence of avian influenza were 10.19% and 25.00%, respectively. There was a significant difference for the positive samples of commercial ducks or muscovy ducks among districts (p<0.05).

In order to detect virus type A and subtype H5N1, 252-throat and cloacal samples (swabs samples) of commercial ducks at live-poultry markets and slaughterhouses as well as 24-swabs samples of muscovy ducks at households were collected and analyzed by using rRT-PCR technique. Results demonstrated that (i) 39.68% of commercial ducks were infected with avian influenza virus (AIV), in which 5.16% and 34.52% of ducks were respectively in H5N1 subtype and other; and (ii) 100% of muscovy ducks were negative. Difference for positive samples among slaughterhouses or live-poultry markets was statistically significant (p<0.05).

In summary, to increase the protective rate of ducks against AIV, especially H5N1 subtype, in Dong Thap, farmers should (i) apply the raising model of biosafety, (ii) usually test prevalence and virulence of AIV towards using vaccine most effectively.

Key words: ducks, muscovy, prevalence, avian influenza virus, H5N1

ABSTRACT

“Molecular characterization of the porcine mannan-binding lectin serine protease 1/3”

NGUYỄN NGỌC THẠCH

Complement system is activated by three different ways - classical, alternative and lectin pathways. In presense of carbohydrate on the surface of microbes, manose-binding lectin (MBL) binds to members of the MBL-serine protease family (MASP1, MASP2 and MASP3) to generate proenzymes activating C4, C2, and C3 of complement system via the lectin and alternative pathways. However, these serine proteases have not been identified in pig yet. Therefore, this study was mainly focused on sequencing of cDNA and analyzing of structural protein of MASP1 and MASP3 molecule in pig.

It was indicated that 3.009 nucleotide of MASP1 cDNA encoding 699 deduced amino acids was sequenced. The MASP1 gene had 16 exons and its protein contained rich-cysteine domains such as CUB1 (a.a 18-138, 121 a.a, 2 cysteine), EGF_CA (a.a 139-182, 44 a.a, 6 cysteine), CUB2 (a.a 185-297, 113 a.a, 4 cysteine) in N-terminus, two CPP domains (CCP1: a.a 301-362, 62 a.a, 4 cysteine and CCP2: a.a 367-432, 66 a.a, 4 cysteine) at the center of protein and Tryp_SPc domain (a.a 448-691, 244 a.a, 7 cysteine) in C-terminus. The putative signal peptide, N-glycosylation sites, catalytic sites and cysteines were also high conserved between human and pig. Compared with human, porcine MASP1 showed 88% identity at protein level. Additionally, three single nucleotide polymorphisms at loci 1.650AàG (AspàGly, exon 12), 1.748CàT (LeuàPhe, exon 13) và 1.807CàT (exon 13) were also found in a population of Landrace breed.

With 2.657 bp and 11 exons, in which the coding region is from nucleotide 152-2388, MASP3 encoded 728 amino acids. There was high homology among mammalian species (pig, human, cattle and dog) at both cDNA (87-90%) and protein (92-94%) levels. Macromolecule MASP3 had 27 cysteine residues. However, amino acid with high percent in its protein included Ser (8,4%), Val (8,1%), Leu (8,0%), Gly (7,6%) and Glu (7,1%). With a molecular mass of approximately 81.55 kilo Daltons, MASP3 was an assembly of rich-cysteine protein domains such as CUB1 (a.a 18-138, 2 cysteine), EGF_CA (a.a 139-182, 6 cysteine), CUB2 (a.a 185-297, 3 cysteine), CCP1 (a.a 301-362, 4 cysteine), CCP2 (a.a 367-432, 4 cysteine) in N-terminus and Tryp_SPc (a.a 449-711, 5 cysteine) in C-terminus. The Tryp_SPc is the largest domain whereas EGF_CA is the smallest. Besides those, a signal peptide (a.a 1-19), 13 disulfide bonds, 5 N-glycosylation sites, and methionine loop (a.a. 630-649) were also identified.

These results provide valuable information for breeding program towards disease resistance in pigs in the future.

Key words: MASP1, MASP3, cDNA, protein, molecular characteristics, pig

ABSTRACT

“Effects of housing-system and feeding-method on growth perfomance of the finishing pigs”

THÁI BÍCH TUYỀN

This study consisted of two experiments (i) investigating pig production status and (ii) evaluating effects of housing-types and feeding-methods on performance of finishing pigs in Soc Trang province.

The investigation results demonstrated that (i) pig production system with a small-scale (81,82%) was mostly found, (ii) most of the raisers using cross-breeds and different feed sources (i.e. 58% commercial feed) and feeding methods (84,49% ad-bilitum, 57,22% dry-feed ) had good experiences in pig production, (iii) vaccination program was often focused on deaseases such as pasteurellosis (67,91%), salmonellosis (67,38%), pestis sum disease (68,45%), (vi) up to 71,66% of pig farms was installed with the waste-treating system.

Another study was conducted in a cross-bred group Duroc x (Landrace x Yorkshire) from 60g to slaughtering. Therefore, pigs were allotted in a design of completely randomized blocks (dry and rainy seasons) with 3 factors (opened and closed-housing types, ad-bilitum and limited feeding methods, female and male genders) and two recipiations. There were a total of 32 experimental units (40-48 finishers/ unit). Experiment results indicated that (i) housing-terperature and humididy had an effect on daily feed-intake of the finishers according to the regression equation Y = - 115,1 + 2,970X – 0,01881X2, (ii) average daily gain of pigs raised in the closed-housing system was higher than in the opened-one (789,83 vs 740,25, P<0,01), meanwhile the FCR was in contrast between two housing systems (2,59 vs 2,85, P<0,05), significantly, (iii) effects of temperature and humidity on body performance traits were found significantly (P<0,01), and (iv) using the closed-housing system in pig production could reduced 19,03% of feed cost.

In summary, cross-bred pigs raised in the closed-housing system gave much more economic efficiency than in opened one. Feeding methods did not affect growth performance and feed convertion ratio in pigs.

Keywords: pig, temperature, humidity, housing-systems, feeding-methods, performance, FCR.

INTRODUCTION

"Association of single nucleotide polymorphism of growth hormone gene with carcass traits in the tau vang chicken breed of Vietnam"

JOSEPH MATEY

Most economic traits in farm animals show continuous variation and the fundamental genetic nature is very complex (Li et al., 2010) as it is controlled by a combination of genes and the environment. Genetic variation exists among organisms because of variation in the DNA sequence. DNA variations are mutations resulting from substitution of single nucleotides polymorphisms (SNPs), insertion or deletion of DNA fragments of various length, or duplication or inversion of DNA fragments (Teneva and Petrovic, 2010). Improving economic traits in chicken has increasingly become of interest and the identification and utilization of quantitative trait loci (QTL) provides the potential for genetic improvement in selection programs without slaughtering. Recent advances in molecular genetics have led to the discovery of genes, or markers associated with genes, that affect meat quality (Gao et al., 2007). Genetic diversity in local or domestic breeds of animals allows breeders and researchers to modify the genetic characteristics of these local breeds in response to changes in environment, diseases or market conditions and maintain genetic diversity as well as improve productivity.

The application of genetic selection methods in the poultry industry has resulted in an increased growth rate and carcass quality (Zhou et al., 2005). However, as a consequence, incidence of health related problems such as obesity, sudden death syndrome and leg problems because of intensive application of these selection methods has also increased (Kadlec et al., 2011). The use of molecular marker-assisted selection has proven to be efficient and helpful to concurrently improve animal production and health (Zhou et al., 2005; Li et al., 2008). The identification of candidate genes associated with various QTL for egg and meat production is a tool to investigate the associations of gene polymorphisms with economically important traits (Zhou et al., 2005) and to promote efficient selection for breeding purposes in livestock species (Altmann and Von Borell, 2007). Identification of these candidate genes allows to study the relationship between SNPs in genes and trait of interest that are likely to be associated with the physiological pathways underlying those traits (Gao et al., 2007; Shin and Chung, 2007).

Single nucleotide polymorphisms (SNPs), also referred to as “snip”, represent the most innovative molecular markers in genotyping studies (Teneva and Petrovic, 2010). SNPs are a type of DNA polymorphism which is bi-allelic, abundant in the genome, genetically stable and adaptable to high output automated analysis (Beuzen et al., 2000; Vignal et al., 2002) and occurs either in genes 15 (i.e., promoter, exons or introns) or between genes (Emara and Kim, 2003). SNPs have already been used in animal identification and paternity analysis in American and European beef and dairy breeds and in analysis on genetic distance (Teneva and Petrovic, 2010).

The genes of somatotropic axis in chicken, as in mammals, are the primary regulators of growth and development (Nie et al., 2005). Hence these genes could function as candidate genes for the evaluation of their effects on chicken growth, carcass and meat quality traits (Lei et al., 2008). The axis consists of essential components such as growth hormone (GH), insulin-like growth factors (IGF –I and II) their associated carrier proteins and receptors and other hormones such as insulin, leptin and thyroid hormones (Kadlec et al., 2011; Nie et al 2005).

Insulin associated with the somatotropic axis is a peptide hormone secreted by the β cells of the pancreatic islets of Langerhans (Poitout et al., 2006) and plays an essential role in the maintenance of blood glucose level by facilitating cellular uptake of glucose, regulating carbohydrate, lipid and protein metabolism as well as promoting cell division and growth through mitogenic effect (Wilcox, 2005). Insulin also plays an important role in potassium homeostasis (Qui et al., 2006). Insulin acts to increase the energy storage as glycogen in the liver and muscles and triglyceride in adipose tissue (Scanes, 2011). In view of this, the insulin (INS) gene is considered as a candidate gene in genetic analysis for complex traits like growth rate, body composition and fat deposition, traits which are of economic importance in the poultry industry (Qui et al., 2006).

The growth hormone (GH) as it is for other mammalian species, is indispensable for normal growth and development of avian species (Lei et al., 2008). The GH is a polypeptide which is synthesized in and secreted by the pituitary gland. In chicken, it is involved in physiological functions such as body composition, egg production and reproduction (Ip et al., 2001; Nie et al., 2002). The GH influences performance traits and plays an essential role in growth and metabolism (Enayati and Rahimi-Mianji, 2009; Nie et al., 2005). There are numerous SNPs in the chicken GH gene and some of which have been strongly linked to weight gain and skeletal weight (Harvey, 2013), carcass characteristics (Ip et al., 2001; Nie et al., 2005 Lei et al, 2007) egg production (Feng et al., 1997) and disease resistance (Kuhnlein et al., 1997).The growth hormone gene has been studied in various animal species such as pigs (Cheng et al., 2000), bovines, goat (Wickramaratne et al., 2010) as well as polymorphisms in the chicken’s GH gene (Ip et al., 2001; Nie et al., 2002; Nie et al., 2005). The growth hormone receptor (GHR) mediates the biological actions of GH on target 16 cells by transducing the myogenic-stimulating signals across the cell membrane and inducing the transcription of many genes including insulin-like growth factor -1 (IGF-1). In view of this, GH and GHR genes have been considered important candidate genes for the identification of genetic markers for growth and carcass traits in livestock (Ge et al., 2003). The growth hormone secretagogue receptor (GHSR), a member of the G-protein-coupled receptor family is involved in numerous physiological functions such as pituitary growth hormone secretion, food intake and energy expenditure (Shuto et al., 2002) and thus has been considered as a candidate gene for chicken production performance (Fang et al., 2010).

The purpose of this internship was to assist in the investigation of polymorphisms in growth hormone (GH), insulin (INS), growth hormone receptor (GHR) and growth hormone secretagogue receptor (GHSR) genes in three different chicken populations (Tau Vang, Noi and Cobb 500 breeds) raised in Vietnam and to evaluate associations between the GH gene and carcass characteristics in Tau Vang native chicken breed which is gradually dominating the native chicken breeds because of its nutritious meat quality and ability to withstand harsh environmental conditions (Khang and Ogle, 2005).

PREFACE

"Evaluating the effluent management in Vietnamese pig farms"

LE DANG MINH

There is an increasing trend in Vietnamese livestock production in recent years. This trend leads to a sustainable rise in the large amount of wastes produced from the animal production activities. Based on the treatment technology and management of animal manure, it can be a positive or negative thin. It can be useful as nutrient source supporting animal production or it can be a hazard to the environment. Animal manure contains a lot of organic matter (OM) like Nitrogen (N), Phosphorous (P), Potassium (K) and inorganic matter. In order to re-use the high nutrient source of animal manure the farmers need to apply proper manure treatment technologies and management practices. If there is no proper way of treating or managing manure, it can cause a huge environmental pollution with issues affecting the activity of livestock production and farmer‟s life.

The scope of this thesis is to evaluate animal manure management in Vietnamese pig farms when they apply the traditional manure management and introduce the efficacy and feasibility of manure management and in the application of the module, focusing on the specialization in animal production in Vietnam.

The study is divided into 7 Chapters. Chapter 1 and chapter 2 will introduce the point of view of Vietnamese Pig farms in the practices of manure management. The application and the environmental risks caused by pig sewage will also be discussed in this chapter. Chapter 4 will illustrate the manure treatment in pig farms. Chapter 5 creates a short description about manure management and application modules, which is applied and can be utilized in Vietnamese pig farms. The two last chapters involve the discussions & comparisons of the benefits and disadvantages of manure treatment methods and the feasibility of these manure management modules, creating a conclusion to the whole study.

ABSTRACT

"Effects of genetic variation of TSH-beta on meat traits in Tau Vang chickens"

CHÂU THIỆN NGỌC

The study was conducted to analyze relationship between genetic variation of TSH-β with growth, meat yield and meat quality traits in Tau Vang chicken. Polymorphism at nucleotide T1761C and G1821A was identified by using PCR/RFLP technique in digestion of restriction enzyme Hin6I and MspI, respectively. Genotypic and allelic frequencies at these polymorphisms were found in Hardy-Weinberg equilibrium. Analyzing results revealed that (i) two polymorphic sites were found at locus T1761C in the TSH-β gene with genotype frequency of CC=0,08, CT=0.50 and TT=0.42 as well as locus G1821A with genotype frequency of AA=0.02, AG=0.35 and GG=0.63;(ii) at locus T1761C, statistically significant difference among genotypes for pH value at 15 minute post-slaughter and ether extract of thigh meat and calcium of breast meat was found. Chickens with CC genotype had highest value of ether extract of thigh meat and calcium of breast meat. In addition, polymorphism at locus G1821A was significantly associated with feed conversion ratio as well as pH value of thigh meat at 15 minutes and 48 hours post-slaughter; and (iii) the statistical significance interaction between sex and T1761C genotype on abdominal fat rate of breast meat and driploss at 6 hours post-slaughter was also indicated. Chicken with CC genotype in the CTU-BT01 strain showed calcium concentration of breast meat higher than CT and TT genotype. Beside that, at locus G1821A, significant difference was found on some traits, such as feed conversion ratio, weight rate of thigh and breast, where the chicken with AA genotype is the best.

This study has provided further important evidence for effects of TSH-β polymorphism on express of growth, meat yield and meat quality traits in Tau Vang chicken. This should be applied to design SNP-MarkerAssisted Selection for improving economic trait in chicken.

Keywords: TSH-β gene, polymorphisms, Tau Vang chicken, meat traits.

ABSTRACT

"Relation between polymorphisms of leptin candidate gene and meat traits in Tau Vang chickens"

CAO CHI NGUYEN

The study was conducted to analyze the relationship between genetic variation of Leptin with growth, meat yield and quality traits in Tau Vang chickens. Polymorphisms at nucleotide C352T and G427A were identified by using PCR/RFLP technique in digestion of restriction enzyme Bsh1236I, respectively. Genotypic and allelic frequencies at these polymorphisms were found in Hardy-Weinberg equilibrium. Analyzing results revealed that: i) Two polymorphic sites were found at locus C352T (CC=0.34, CT=0.40 and TT=0.26) and at locus G427A (AA=0.34, AG=0.51 and GG=0.15) in the Leptin gene; ii) Both polymorphisms affect some meat traits such as percentage of breast meat, thigh length, abdominal fat, calcium concentration of breast meat, pH and driploss in Tau Vang broilers. These should be applied to design SNP-MarkerAssisted Selection for improving economic traits in chicken.

Keywords: Leptin gene, polymorphisms, Tau Vang chicken, meat yields, meat traits.

ABSTRACT

"Effects of genetic variation of GHSR on growth performance and meat traits in Tau Vang chickens"

NGUYỄN CÔNG HẬU

The study was conducted to analyze relationship between genetic variation of GHSR gene with growth, meat yield and quality traits of Tau Vang chicken. Polymorphism at nucleotide G656A and C3678T was identified by using PCR/RFLP technique in digestion of restriction enzyme MspI and Bsp119I. Genotypic and allelic frequencies of these polymorphisms were found in Hardy-Weinberg equilibrium. Analyzing results revealed that: (i) two polymorphic sites were found at locus G656A in the GHSR gene with genotype frequency of AA=0,01; AG=0,13 and GG=0,87 as well as locus C3678T with genotype frequency of CC=0,82; CT=0,18 and TT=0,00; (ii) at locus G656A, statistically significant difference among genotypes for ash content of breast muscle and body weight after displume percentage. Chickens with AG genotype had highest value of gain, body weight at 13 weeks, leg skeletal weight. In addition, polymorphism at locus C3678T was significantly associated with dry matter and ether extract of leg muscle where the chicken with CT is the best; and (iii) the statistical significance interaction between line and G656A genotype on abdominal fat rate, body weight after displume percentage and pH of thigh muscle (at 15 minutes, 24 hours, 48 hours) as well as breast muscle (24 hours, 48 hours) post-slaughter was also indicated. Chicken with GG genotype in the CTU-BT01 and CTU-LA01 had ash content of breast muscle higher than the other genotype. Beside that, at locus C3678T, significant difference was found on some traits, such as gain, feed intake and pH at 24 hours of thigh muscle after slaughter, where the chicken with CT genotype in the CTU-BT01 and CC genotype in the CTU-LA01 is the best. This study has provided further important evidence for effects of GHSR polymorphism on express of growth, meat yield and meat quality traits in Tau Vang chicken. This should be applied to design SNP-MarkerAssisted Selection for improving economic trait in chicken.

Keywords: GHSR gene, polymorphisms, Tau Vang chicken, meat yields, meat traits.

ABSTRACT

"Effects of genetic variation of IGF1 and GHR on growth performance and meat traits in Tau Vang chickens"

NGUYỄN VĂN TRUYỀN

The study was conducted in a total of 218 Tau Vang chicken including two different lines CTU-LA01 and CTU-BT01. Objective of this study is to analyze relationship between genetic variation of IGF1 and GHR with growth, meat yield and meat quality traits in Tau Vang chicken. Polymorphism at nucleotide A565G/GHR and A867C/IGF1 was identified by using PCR-RFLP technique in digestion of restriction enzyme Eco72I and HinfI, respectively. Genotypic and allelic frequencies at these polymorphisms were found in Hardy-Weinberg equilibrium. Analyzing results revealed that (i) two polymorphic sites were found at locus A867C/IGF1 with genotype frequency of AA=0,01, AC=0,30 and CC=0,69 and locus A565G/GHR with genotype frequency of AA=0,85, AG=0,14 and GG=0,01; (ii) at locus A867C/IGF1, statistically significant difference among genotypes for average daily gain, body weight, body weight after draining blood, body weight after removing feathers, carcass weight, breast muscle weight, thigh weight, thigh bone weight, abdomial fat weight and percentage, breast length, thigh length, dry matter, Ash content and water holding capacity of breast meat; (iii) in addition, polymorphism at locus A565G/GHR was significantly associated with body weight after draining blood, body weight after removing feathers, carcass weight and percentage, breast weight, breast muscle weight, thight weight ratio, thigh muscle weight, breast length, calcium content of thigh meat and pH value of breast and thigh muscle at 24 hours post-slaughter; (iv) the statistical significance interaction between strain and genotype at locus A867C/IGF1 and locus A565G/GHR on Ash content of breast meat and calcium content of thigh meat, respectively.

This study has provided further important evidence for effects of IGF1 and GHR polymorphism on express of growth, meat yield and meat quality traits in Tau Vang chicken. This should be applied to design SNP-MarkerAssisted Selection for improving economic traits in chicken.

Keywords: IGF1 gene, GHR gene, polymorphism, Tau Vang chicken, meat yield, meat quality.

ABSTRACT

"Use of feed sources for beef cattle and productivity of some grass seeds in an giang province"

NGUYỄN NI LÊ

Eperiment 1: The survey was conducted from May 2016 to February 2017 from Chau Phu, Cho Moi, Tri Ton and Tinh Biên in An Giang province to assess farming techniques and productivity of cattle. The survey with 205 cattle farms showed in An Giang province, cattle are raised for meat, breeding and draft power. Many households still follow traditional methods of farming. Chau Phu and Cho Moi were good invested in housing and nutrient supply and good care as well to fatten cattle here they give good growth rate and quality. In contrast, investment at Tri Ton and Tinh Bien remains limited, cattle are kept for time longer for work, breeding cattle productivity in these two districts are not high, farming practice is inefficient Attention should be paid to support technical, funding and planning for cattle producers in An Giang to develop the cattle industry, bringing higher economic efficiency.

Eperiment 2: The study was conducted to evaluate the effects of two levels of fertilizer and five grass species on adaptive capacity and productivity at An Giang province. The experiment was 2 x 5 factorial layout in a randomized complete block design with five grass species (Sorghum, Panisetum purpurcum, Panicum maximum TD 58, Panicum maximum c.v. Mombasa and Setaria sphacelata) and two levels of inorganic fertilizer (CT1: ure 250 kg/ha/year; phosphate 500kg/ha/year; potassium 200 kg/ha/ year and CT2: ure 350 kg/ha/year; phosphate 750 kg/ha/year; potassium 350 kg/ha/year), three replications, equivalent to 30 experimental units-giving a total of 30 plots with 100 m2 each. First cutting was 60 days after planting and next cutting at 45 days. Parameters were ability of growth, biomass yield and chemical composition. The results from soil analysis and pH water measurement reveal that grass species were cultivated on acidity soil and low nutrition. The results from study suggest that adaptive capacity of Sorghum¬ was lower than other grass species due to decrease biomass yield from first cutting to third cutting. Five grass species have improved the biomass yield when they were applied with CT2, but the responses to fertilizer among grass species were different.

Keywords: survey, techniques, productivity, cattle, acid soil, grass, fertilizer.