Genetic and morphometric characterization of a local Vietnamese Swamp Buffalo population     

C. Berthouly  X. Rognon  T. Nhu Van  A. Berthouly  H. Thanh Hoang  B. Bed'Hom  D. Laloë  C. Vu Chi  E. Verrier  & J.-C. Maillard 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2010,127(1):74-84

The water buffalo plays a key role in the socio-economy of South-East Asia as it is the main draught power for paddy rice cultivation. While in the Indian subcontinent the water buffalo is the riverine type, in South-East Asia the majority of buffaloes are of the swamp type. In the poor remote northern province of Ha Giang in Vietnam, improvement of the swamp buffalo breed may be one of the best ways to increase sustainability of farming systems. Therefore, analysis of the genetic structure of the province buffalo population is a prerequisite to any conservation or improvement project. A total of 1122 animals were described for 11 body and horn measurements for morphometric characterization. From this sample set, 744 animals were genotyped for 17 microsatellite markers. Also 17 animals from southern provinces of Vietnam were genotyped as a comparative sample. The results showed that genetic diversity as well as inbreeding value in the Ha Giang was high. The F _ST values within the province and across Vietnam were low indicating that most of the population variation is explained by individual variability. Bayesian clustering analysis did not highlight the presence of subdivided populations. These results are useful for the implementation of a conservation and improvement strategy of the swamp buffalo in order to guarantee the householders' needs for sustainability of the farming system in the Ha Giang province.  相似文献   

Effect of thinning intensity on tree growth and temporal variation of seed and cone production in a Pinus koraiensis plantation     

Thanh Tuan Nguyen  Dinh Tien Tai  Peng Zhang  Muhammad Razaq  Hai-Long Shen 《林业研究》2019,(3):835-845

Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.  相似文献   

Experimental assessment of the effects of sublethal salinities on growth performance and stress in cultured tra catfish (Pangasianodon hypophthalmus)     

Phuc Trong Hong Nguyen  Huong Thi Thanh Do  Peter B. Mather  David A. Hurwood 《Fish physiology and biochemistry》2014,40(6):1839-1848

The effects of a range of different sublethal salinities were assessed on physiological processes and growth performance in the freshwater ‘tra’ catfish (Pangasianodon hypophthalmus) juveniles over an 8-week experiment. Fish were distributed randomly among 6 salinity treatments [2, 6, 10, 14 and 18 g/L of salinity and a control (0 g/L)] with a subsequent 13-day period of acclimation. Low salinity conditions from 2 to 10 g/L provided optimal conditions with high survival and good growth performance, while 0 g/L and salinities >14 g/L gave poorer survival rates (p < 0.05). Salinity levels from freshwater to 10 g/L did not have any negative effects on fish weight gain, daily weight gain, or specific growth rate. Food conversion ratio, however, was lowest in the control treatment (p < 0.05) and highest at the maximum salinities tested (18 g/L treatment). Cortisol levels were elevated in the 14 and 18 g/L treatments after 6 h and reached a peak after 24-h exposure, and this also led to increases in plasma glucose concentration. After 14 days, surviving fish in all treatments appeared to have acclimated to their respective conditions with cortisol levels remaining under 5 ng/mL with glucose concentrations stable. Tra catfish do not appear to be efficient osmoregulators when salinity levels exceed 10 g/L, and at raised salinity levels, growth performance is compromised. In general, results of this study confirm that providing culture environments in the Mekong River Basin do not exceed 10 g/L salinity and that cultured tra catfish can continue to perform well.  相似文献   

Genetic analysis of host–pathogen incompatibility between Lolium isolates of Pyricularia oryzae and wheat     

Trinh Thi Phuong Vy  Gang-Su Hyon  Nguyen Thi Thanh Nga  Yoshihiro Inoue  Izumi Chuma  Yukio Tosa 《Journal of General Plant Pathology》2014,80(1):59-65

Lolium isolate TP2 of Pyricularia oryzae, causal agent of gray leaf spot of perennial ryegrass (Lolium perenne), is virulent on perennial ryegrass, but avirulent on wheat cultivars. Genetic analysis of wheat F₂ populations revealed that the resistance of wheat cultivars Chinese Spring, Shin-chunaga, and Norin 4 to TP2 was conditioned by two genes, R1 and R2. R1 was highly effective, while R2 was less effective. The strong resistance gene R1, designated Rmg6, was mapped on chromosome 1D using microsatellite markers. For revealing genetic mechanisms of avirulence, TP2 was crossed with Triticum isolate Br48. Segregation analysis of their F₁ progenies revealed that the avirulence of TP2 on the three wheat cultivars was conditioned by two unlinked genes, one (A1) highly effective and the other (A2) less effective. These results suggest that the incompatibility between TP2 and the common wheat cultivars is conditioned by two gene pairs; the Rmg6–A1 interaction results in strong resistance, and the R2–A2 interaction results in moderate resistance.  相似文献   

Agrotourism and fast urbanisation: The double pressure of development on peri-urban agriculture in Hôi An,a small city of central Vietnam     

Thi Thanh Hiên Pham  Hai Son Cao  Dominic Lapointe 《Asia Pacific viewpoint》2023,64(3):408-424

Agrotourism in Vietnam has been identified as one of the strategies used to achieve green growth and countryside modernisation, and it is often included as part of the national and local agenda. In this paper, we examine agrotourism in a village in the periphery of Hội An city (an international tourism hub in central Vietnam) to question tourism's interaction with ongoing development processes. More specifically, we aim to understand the impact of fast peri-urbanisation on agrotourism and the impacts of agrotourism on people's daily lives, specifically when it comes to physical changes in their living environment, tensions in their social life and their concerns about the future. Our analysis is supported with data generated from interviews with farmers, local officials, tourism workers and tourists. We find that agrotourism products lacked authenticity and farming was not of great interest for tourists, yet the state's investment in the village tended to favour spaces and infrastructure that could attract more tourists and generate profit, to the detriment of cultural infrastructure. Land speculation and an unequal distribution of income were the main tensions in the village along with farmers' concerns about their rural heritage, income diversification and environmental quality. As such, agrotourism in the village has been driven by rapid urbanisation and mass tourism, creating a competition between a consumption activity and a productive activity. Those are important parameters that future policymakers need to take into consideration in order to sustain the city's food production and tourism.  相似文献   

Sodium fluoride influences calcium metabolism resulting from the suppression of osteoclasts in the scales of nibbler fish <Emphasis Type="Italic">Girella punctata</Emphasis>     

Masayuki Sato  Koji Yachiguchi  Keiichi Motohashi  Yukio Yaguchi  Yoshiaki Tabuchi  Yoichiro Kitani  Takahiro Ikari  Shouzo Ogiso  Toshio Sekiguchi  Tran Ngoc Hai  Do Thi Thanh Huong  Nguyen Viet Hoang  Makoto Urata  Hiroyuki Mishima  Atsuhiko Hattori  Nobuo Suzuki 《Fisheries Science》2017,83(4):543-550

The influence of sodium fluoride (NaF) on calcium metabolism was examined in nibbler fish (marine teleosts). Two days after the administration of NaF (5 μg/g of body weight) (around 10^?4 M in fish), we showed that plasma calcium levels significantly decreased in NaF-treated nibbler fish. In addition, we detected fluoride in the treated scales by use of a scanning electron microscope with an energy-dispersive X-ray microanalysis, indicating that NaF directly affects their scales. Therefore, the influence of NaF on osteoblasts and osteoclasts in the scales was examined. In the scales of NaF-injected nibbler fish, tartrate-resistant acid phosphatase (TRAP) (osteoclastic marker enzyme) decreased, although alkaline phosphatase (osteoblastic marker enzyme) was activated. To confirm the effect of NaF on osteoclasts, furthermore, the mRNA expressions of osteoclastic markers (matrix metalloproteinase-9 and TRAP) were decreased significantly 2 days after incubation. In barred knifejaws, plasma calcium levels decreased as they did in nibbler fish. Therefore, NaF functions in both osteoblasts and osteoclasts and then influences calcium metabolism in marine fish. In the marine environment, high levels of fluoride (1.2–1.5 mg F^?/l) (around 10^?5–10^?4 M) are present in seawater. It is probable that teleosts living in seawater efficiently use fluoride to regulate their blood calcium levels.  相似文献   

Effects of replacing fish meal with soya protein concentrate on growth,feed efficiency and digestibility in diets for snakehead,Channa striata          下载免费PDF全文

Tran Thi Thanh Hien  Tran Minh Phu  Tran Le Cam Tu  Nguyen Vinh Tien  Pham Minh Duc  David A Bengtson 《Aquaculture Research》2017,48(6):3174-3181

Soya bean meal‐based formulated feeds have recently become available for snakehead culture in Vietnam. This study was conducted to determine the appropriate replacement of fish meal (FM) protein by another soya product, soya protein concentrate (SPC), in snakehead (Channa striata) diets. Five iso‐nitrogenous (45% crude protein) and iso‐caloric (19 KJ g^?1) practical diets were formulated to replace 0% (control), 40%, 60%, 80% and 100% of protein FM by protein SPC (100% FM, 40% SPC, 60% SPC, 80% SPC and 100% SPC respectively). A digestibility experiment was also conducted with the same formulated diets with addition of 1% chromic oxide. Fish fed 100% FM and 40% SPC diets had significantly better growth and survival compared with other treatments. Feed intake, feed conversion ratio, protein efficiency ratio and net protein utilization, trypsin and chymotrypsin activities of experimental fish fed 100% FM and 40% SPC diets were significantly higher than those fed other diets. The apparent digestibility coefficient (ADC) of the diet and diet components, ADC_diet, ADC_protein and ADC_lipid, of fish fed diet 40% SPC and 100% FM treatment were significantly higher than those of other treatments. The cost/kg fish produced in diets 100% FM and 40% SPC was much lower compared with other treatments. Dietary inclusion levels of SPC in diet above 40% significantly affected fish survival, growth, digestibility and trypsin and chymotrypsin activities, although fish chemical composition was not greatly affected.  相似文献   

Weaning methods using formulated feeds for snakehead (Channa striata and Channa micropeltes) larvae          下载免费PDF全文

Tran Thi Thanh Hien  Bui Minh Tam  Tran Le Cam Tu  David A Bengtson 《Aquaculture Research》2017,48(9):4774-4782

The culture of snakehead fish (Channa striata and Channa micropeltes) in Vietnam is limited, and snakehead culture has been banned in Cambodia, because traditional practices include capture of fingerlings from the wild as seed, as well as capture of small‐size (also known as trash fish or low‐value) fish. As hatchery breeding technology has improved, we investigated the optimal weaning practices for these two species. Both laboratory experiments and farm trials were conducted. For C. striata, the optimal weaning procedure is to begin at 17 days after hatch (dah) and wean the fish at 10% replacement of live feed with formulated feed per day. However, for C. micropeltes, the optimal procedure is to wait until 40 dah to begin weaning and then to wean the fish with a 10% replacement of live feed with formulated feed every 3 days. These results should enable farmers to domesticate snakehead culture in Vietnam and Cambodia and eliminate reliance on fish captured from the wild as both seed and feed.  相似文献   

The determinants of detecting veterinary drug residues: Evidence from shrimp farmers in southern Viet Nam     

Guenwoo Lee  Aya Suzuki  Hoang Nam Vu 《Aquaculture Economics & Management (Blackwell Science)》2019,23(2):135-157

While export-oriented shrimp farming has become an important source of income for many small-scale farmers in developing countries, the rate at which products are rejected at the ports of developed countries has remained high mainly due to the overuse of antibiotics. To reveal what determines the overuse of antibiotics, we interviewed 201 shrimp farmers in Viet Nam in 2015 and collected shrimp samples from each household’s pond for the screening of residual drugs. These tests revealed that residual drugs exceeding acceptable limits by Japanese standards were found in the samples of 40 farmers. We conducted cross-sectional Logit and Tobit regressions to examine whether results of the residue tests are significantly associated with farmers’ characteristics and management practices. This study finds that: (1) receiving BMP training has a significant and positive effect on reducing residual drugs; (2) if farmers know multiple extension officers, these relationships have significant and positive effects on reducing residual drugs; and (3) farmers with experience of shrimp disease outbreaks reduce use of antibiotics. Overall, this study contributes to revealing the determinants of detecting veterinary drug residues in shrimp farming in multiple (social, economic and psychological) dimensions.  相似文献   

Effects of natural dietary carotenoids on skin coloration of false Clownfish (Amphiprion ocellaris Cuvier, 1830)     

Hua Thai Nhan  Tran Xuan Minh  Hon Jung Liew  Tran Thi Thanh Hien  Rajesh Jha 《Aquaculture Nutrition》2019,25(3):662-668

This study was performed to evaluate the effect of dietary natural carotenoid sources on skin colour enhancement of false clownfish Amphiprion ocellaris. The juvenile fish (initial body wt. 0.30 g) were fed with four experimental diets including (a) commercial feed (reference diet), (b) moist feed, (c) sweet potato (potato diet) and (d) dried gut weed Enteromorpha sp. (gut weed diet). Sweet potato and gut weed were used to boost up β‐carotene levels in the diets. There was no significant difference in final weight (0.51 ± 0.02 – 0.61 ± 0.01 g) and length (2.80 ± 0.02 cm) of fishes among treatments (p > 0.05) after 8 weeks. The survival rate of the fish in all dietary treatment was greater than 89%. Principal component analysis results showed that fish fed potato and gut weed diets performed brighter colour in skin with more orangeness, body and accumulated β‐carotene levels were higher than those fish fed with reference diet. Indicator a* value for the redness of fish fed potato diet (16.18 ± 0.59) and gut weed (14.36 ± 2.14) was also higher than fish fed reference diet (10.92 ± 0.82). The result of this study provided key information for developing dietary colour enhancement of ornamental fish by using cost‐effective feed ingredients (potato and gut weed) as natural supplemental carotenoid sources.  相似文献