Nguyen Hoang Thinh

This study aimed to evaluate the polymorphism of the POU1F1 gene and its association with body weight and weight gain in Bach Thao goats. A total of 110 animals (64 males and 46 females) were used, and ear tissue samples were collected for DNA extraction and PCR-RFLP analysis to determine POU1F1 genotypes. Allele and genotype frequencies were subsequently calculated. Three genotypes (TT, TC, and CC) were identified, with the T allele and TT genotype showing the highest frequencies. Body weight at birth, and at 3, 6, and 9 months of age, as well as average daily gain (ADG during the corresponding growth period were recorded. Goats with the TT genotype had significant higher body weight at birth, and at 3, 6, and 9 months of age, together with higher ADG during the corresponding period, than those with the CC genotypes (P < 0.05).. These finding indicates that POU1F1 polymorphism is associated with growth performance in Bach Thao goats and may have potential as a molecular marker for marker-assisted selection to improve growth traits in this breed.

Antibiotic resistance is a major global health threat, and antibiotic use in livestock farming contributes to this issue. The present study aimed to assess the prevalence and antibiotic susceptibility of Escherichia coli (E. coli) isolated from poultry fecal samples in Ninh Binh province, Vietnam. Between May and October 2025, 170 dropping fecal samples were randomly collected from 45 poultry farms in Ninh Binh province, Vietnam, including 24 broiler chicken farms (aged 2.5-3.0 months old) and 21 meat-oriented duck farms (aged 1.5-2.0 months old). Fecal samples were transferred to the laboratory and cultured in peptone buffer and on selective media, including MacConkey agar, eosin methylene blue agar, and triple sugar iron agar. Antibiotic susceptibility was assessed using the disk diffusion method on Mueller-Hinton agar. Suspected E. coli colonies were confirmed using Gram staining and biochemical tests such as citrate utilization, indole production, the methyl red test, and the Voges-Proskauer reaction. Escherichia coli was isolated from 134 (78.8%) fecal samples, including 69/85 (81.2%) chicken and 65/85 (76.5%) duck samples. The susceptibility of E. coli strains to 10 antibiotics was evaluated using the disk diffusion method. Escherichia coli strains isolated from chickens and ducks demonstrated the highest resistance to ampicillin (82.8%), followed by sulfonamides (79.9%), trimethoprim/sulfamethoxazole (74.6%), tetracycline (60.5%), and gentamicin (52.2%). Resistance to the remaining antibiotics, including norfloxacin, doxycycline, nalidixic acid, and cefotaxime, ranged from 14.6% to 38.1%; none of the isolates were resistant to meropenem. Among the isolates, 97 (72.4%) were multidrug-resistant; the proportion of multidrug-resistant isolates from chickens (60 strains, 87.0%) was higher than that from ducks (37 strains, 56.9%). Escherichia coli strains isolated from broiler chicken and duck farms in Ninh Binh, Vietnam, exhibited diverse resistance patterns to several antibiotics. Specifically, 34 and 36 resistance patterns were identified in chicken and duck isolates, respectively, with most isolates having multidrug resistance characteristics.

The Van Linh chicken, an indigenous breed from Lang Son Province, Vietnam, exhibits distinct sexual dimorphism in phenotypic characteristics. Hens (average body

The aim of the study was to investigate the body weights of “I” pigs and the effects of candidate genes (PIT1, H-FABP, CAST, PIK3C3, and GHRH) on growth traits. The pigs were raised in the North of Vietnam. The body weights of 111 pigs at two months of age and of 108 pigs at eight months of age were collected by electronic scales. The average daily gain from birth to two and eight months of age were calculated based on the body weights at two and eight months of age, respectively, and actual days at two and eight months, respectively. The genotypes of PIT1, H-FABP, CAST, PIK3C3, and GHRH genes were identified by PCR-RFLP. Genotypes of these candidate genes and gender were included in the statistical model to analyse the effects of these factors on growth traits. The PIT1, H-FABP, CAST, and PIK3C3 genes did not affect the growth performance of the “I” pigs, while an association between GHRH and growth traits at two months of age was observed. The pigs with AB genotype of GHRH showed heavier body weight at two months of age and faster average daily gain from birth to two months than those with the AA genotype. The body weight at eight months of age and the average daily gain from birth to eight months of gilts were higher than those of barrows. These results suggest that there is potential for improving the productive performance of “I” pigs based on the B allele of GHRH.

Aflatoxin contamination of animal feeds may impact broiler chicken health and production. The adverse impact of aflatoxin can be ameliorated and detoxified by adding capable binding agents, such as Saccharomyces cerevisiae. A total of 648 mixed gender 1-day-old Ross-308 were assigned to a 3 × 2 factorial experiment to investigate the effect of aflatoxin B1 (AF) and Saccharomyces cerevisiae (SAC) on growth performance, blood parameters and carcass characteristics. Chickens were randomly allocated to dietary treatments consisting of three levels of AF at 0, 20 and 60 µg/kg, and with or without SAC (10¹⁰ cells/kg) supplementation of 1 g/kg of dried yeast. Results showed that both AF and SAC increased average daily feed intake (both, p < 0.001) and reduced feed efficiency (p < 0.001 and p = 0.035, respectively), while only AF reduced average daily gain (p = 0.009). Supplementation with SAC improved the average daily feed intake in chickens subjected to AF60 (interaction, p < 0.001), suggesting that SAC could improve the appetite of broilers. Chickens fed AF had a lower carcass weight (p = 0.028) and heart weight (p = 0.031), but higher carcass-normalized weight of gizzard (p = 0.038) and liver (p = 0.010). Aflatoxin administration reduced white blood cells (p = 0.030), lymphocytes (p = 0.029) and basophils (p < 0.001), while increasing neutrophils (p = 0.009). SAC reduced neutrophils (p = 0.004) and mean corpuscular haemoglobin (p < 0.001) while increasing lymphocytes (p = 0.003) and basophils (p = 0.015). The haematological results suggest that AF caused a disturbance in the immune system, compromising the health of the chicken, whereas SAC potentially mitigates these alterations. Dietary AF increased the activity of glutamate oxaloacetate transaminase (p = 0.009). These findings suggest a potential use of Saccharomyces cerevisiae as a natural binder to reduce aflatoxicosis in poultry production systems.

Porcine mucin 4 (MUC4) is a candidate gene for controlling the adhesion of the enterotoxigenic Escherichia coli (ETEC) F4 receptor. Polymorphisms of the MUC4 gene have been used as markers to identify the susceptibility of neonatal diarrhea in piglets for breeding selection. The objective of this study was to evaluate the effects of MUC4 g.243A>G polymorphisms on the production traits of Landrace and Yorkshire pigs in Vietnam. A total of 1,057 Landrace and 1,361 Yorkshire piglets were used to estimate the allelic and genotypic frequencies of the polymorphisms. Body weights at birth, at weaning, at initial fattening (IBW), and at the end of fattening period (FBW), backfat thickness (BFT), and depth of the longissimus dorsi muscle (DLD) were measured and lean meat percentage was estimated. Frequency of the susceptibility allele A to ETEC was higher than the resistance allele G for both breeds based on genotyping piglet tails collected at birth. The AA, AG, and GG genotypes were present in Yorkshire while GG was not found in Landrace. The production traits were not affected (P >0.05) by MUC4 polymorphisms except BFT and DLD (P <0.05). There were interactions between gender and MUC4 genotype (P <0.05) for IBW, FBW, average daily gain, and DLD. These traits of GG males were significantly higher than those of GG females (P <0.05). The results suggest that selecting pigs carrying the GG genotype of MUC4, known as providing resistance to ETEC, do not negatively affect productive performance in Landrace and Yorkshire pigs.

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike’s information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Background: Fertility traits in pigs made a restricted progress through traditional selection. Applying marker assisted selection could improve these traits. The aim of the study was to investigate the effects of candidate genes Estrogen Receptor (ESR), Follicle Stimulating Hormone Beta (FSHB) and Prolactin Receptor (PRLR) on sperm quality traits of Landrace and Yorkshire boars under tropical conditions in Northern Vietnam. Methods: A total of 6306 ejaculates from 140 boars (92 Landrace and 48 Yorkshire) were collected to estimate sperm ejaculate volume (VOL), spermatozoon motility (MO), sperm concentration (CO) and total number of spermatozoon in ejaculate (NT). Ear tissue samples were collected for genotype identification of SNP present in ESR, FSHB and PRLR genes using PCR-RFLP technique. A mixed model was used to test the effect of different genetic and non-genetic factors on the sperm quality traits. Result: The genotype frequencies of ESR, FSHB and PRLR were in Hardy-Weinberg equilibrium for each breed. Age of boars and month of the year had significant effect on all the sperm quality traits (P less than 0.01) while effect of breed was found to be non-significant on all the sperm quality trait. FSHB gene significantly (P less than 0.05) affected VOL, MO and CO. Boars with BB genotype showed positive effect on VOL but negative effect on MO and CO in comparison with AA genotype boars. ESR gene showed only effect on VOL while PRLR affected only MO. Boars with AA and AB genotypes of ESR gene had a significantly higher VOL than those with BB genotype (P less than 0.05). For PRLR gen, AB genotype was associated with higher MO than AA genotype (P less than 0.05). These results suggest a possibility of using the existing polymorphisms in ESR, FSHB and PRLR genes to improve some sperm traits of Landrace and Yorkshire boars.

Thu HDT, Binh NTT, Duc LD, Huu DB, Nhung DT, Xuan CN, Viet LN, Thai AN, Quang ML, Pham DK, Hoang TN. 2020. Indigenous Lien Minh chicken of Vietnam: Phenotypic characteristics and single nucleotide polymorphisms of GH, IGFBP and PIT candidate genes related to growth traits. Biodiversitas 21: 5344-5352. Lien Minh chicken, a Vietnamese indigenous breed, has contributed importantly to the economic development of rural citizens in Cat Ba island, Hai Phong province due to its highly desired characteristics. However, Lien Minh chickens showed a slower growth rate when compared to other industrial chicken breeds. Therefore, the study aims at assessing the appearance characteristics and growth performance of 100 individuals Lien Minh chickens, and investigating the single nucleotide polymorphisms (SNPs) of candidate genes including GH, IGFBP and PIT, which might be associated with growth traits. Blood samples were collected from wing of Lien Minh chickens and used for DNA extraction. Genotyping by the PCR-RFLP method was then conducted. The allele frequencies were 0.97 and 0.03 for alleles A and G of GHi3 gene, respectively. For in IGFBP2 gene, allele frequencies were found as 0.47 for the A allele and 0.53 for G allele. The allele frequencies for PIT1 gene were recorded as 100% for allele B. These polymorphic loci (GHi3, PIT1, and IGFBP2) were followed by the Hardy-Weinberg equilibrium in the Lien Minh chicken population. These were the initial results, which could be used to analyze the correlation of molecular markers and growth traits in Lien Minh chickens.

The alpha (1) fucosyltransferase gene (FUT1) is a candidate gene for controlling the adhesion of Escherichia coli F18 receptor. Indeed, a single-nucleotide polymorphism, c.307G>A, located in the gene is such that pigs with AA genotype are resistant to entero-toxigenic E. coli F18, whereas those with AG and GG genotypes are sensitive. An experiment was carried out in northern Vietnam from March 2016 to May 2017 to determine FUT1 genotype frequencies and the effect of these genotypes on production performance of Yorkshire pigs. A total of 613 animals were genotyped using polymerase chain reaction – restriction fragment length polymorphism method. The body weights at birth, weaning, initial fattening period, and final fattening period were collected from 611, 516, 479, and 418 animals, respectively, whereas backfat thickness, depth of longissimus dorsi, and lean meat percentage were recorded from 328 animals. The frequencies of FUT1 genotypes were found to be in Hardy–Weinberg equilibrium (P = 0.51). Effect of FUT1 genotype was not observed for all production traits (P > 0.05), whereas final body weight and depth of longissimus dorsi were significantly different between females and males (P < 0.05). These results suggest that selection of Yorkshire pigs resistant to entero-toxigenic E. coli F18 could be effective without adversely affecting average daily gain and lean meat.