Use of urea-molasses-multinutrient block and urea-treated rice straw for improving dairy cattle productivity in Vietnam

After conducting a preliminary survey, a feeding trial was carried out to determine the effect of urea-molasses-multinutrient block (UMMB) and urea-treated rice straw (UTRS) as a feed supplement on the productivity of dairy cows. Sixty Holstein-Friesian crossbred cows on 11 smallholder farms were divided equally into control, UMMB and UTRS supplementation groups. Milk yield and feed intake were recorded daily. Milk fat content, body weight and body condition score (BSC) of each cow were determined at two week intervals. Milk samples for progesterone analysis were collected once a week commencing one month after parturition. Data were recorded for date of onset of ovarian activity, estrus, insemination, and conception rate. Milk production increased by 10.3-11.9% and milk fat content increased by 3-5%, therefore, profit for farmers increased by US $0.55-0.73 per cow per day (exchange rate US $1 = VN $11,000). The intervals from calving to onset of ovarian activity (91-94 days), to estrus (110-114 days), to conception (121-122 days) and the calving interval (13.4-13.6 months) in the trial groups were significantly shorter than those in the control group (112, 135, 152 days and 14.4 months, respectively.     

A non-destructive approach for assessing decay in preservative treated wood

This study investigated the suitability of the non-destructive vibration-impulse excitation technique to assess the attack of preservative-treated wood in contact with the ground. Small stakes (10×5×100 mm³) of treated and untreated Scots pine sapwood were exposed to decay in laboratory-scale terrestrial ecosystems. Different soils were used to prove the influence of different types of wood destroying micro-organisms. Wood decay was monitored periodically for one year by determining mass losses and changes in dynamic modulus of elasticity. The results show a large variability in resistance against attacking fungi, depending on wood preservative and soil type. The non-destructive approach using the dynamic modulus of elasticity proved to be a good and sensitive tool for assessing the attack of stakes in laboratory soil testing.     

A new ent-kaurane diterpenoid from Croton tonkinensis leaves

A new ent-kaurane diterpenoid (1) was isolated from the leaves of Croton tonkinensis. The structure of 1 was determined as ent-7beta-hydroxy-15-oxokaur-16-en-18-ol from spectroscopic methods.     

Production of Wild Buffalo (Bubalus arnee) Embryos by Interspecies Somatic Cell Nuclear Transfer Using Domestic Buffalo (Bubalus bubalis) Oocytes

The objective of this study was to explore the possibility of producing wild buffalo embryos by interspecies somatic cell nuclear transfer (iSCNT) through handmade cloning using wild buffalo somatic cells and domestic buffalo (Bubalus bubalis) oocytes. Somatic cells derived from the ear skin of wild buffalo were found to express vimentin but not keratin and cytokeratin‐18, indicating that they were of fibroblast origin. The population doubling time of skin fibroblasts from wild buffalo was significantly (p < 0.05) higher, and the cell proliferation rate was significantly (p < 0.05) lower compared with that of skin fibroblasts from domestic buffalo. Neither the cleavage (92.6 ± 2.0% vs 92.8 ± 2.0%) nor the blastocyst rate (42.4 ± 2.4% vs 38.7 ± 2.8%) was significantly different between the intraspecies cloned embryos produced using skin fibroblasts from domestic buffalo and interspecies cloned embryos produced using skin fibroblasts from wild buffalo. However, the total cell number (TCN) was significantly (p < 0.05) lower (192.0 ± 25.6 vs 345.7 ± 42.2), and the apoptotic index was significantly (p < 0.05) higher (15.1 ± 3.1 vs 8.0 ± 1.4) for interspecies than that for intraspecies cloned embryos. Following vitrification in open‐pulled straws (OPS) and warming, although the cryosurvival rate of both types of cloned embryos, as indicated by their re‐expansion rate, was not significantly different (34.8 ± 1.5% vs 47.8 ± 7.8), the apoptotic index was significantly (p < 0.05) higher for vitrified–warmed interspecies than that for corresponding intraspecies cloned embryos (48.9 ± 7.2 vs 23.9 ± 2.8). The global level of H3K18ac was significantly (p < 0.05) lower in interspecies cloned embryos than that in intraspecies cloned embryos. The expression level of HDAC1, DNMT3a and CASPASE3 was significantly (p < 0.05) higher, that of P53 was significantly (p < 0.05) lower in interspecies than in intraspecies embryos, whereas that of DNMT1 was similar between the two types of embryos. In conclusion, these results demonstrate that wild buffalo embryos can be produced by iSCNT.     

Comparison of Vietnamese and European pig breeds using microsatellites

This study characterized autochthonous pig breeds of Vietnam and compared them with breeds from other regions. A total of 343 animals were considered from 5 indigenous pig breeds of Vietnam (Muong Khuong, Co, Meo, Tap Na, and Mong Cai), 2 exotic breeds kept in Vietnam (Landrace and Yorkshire), 3 European commercial breeds (German Land-race, Piétrain, and Large White), the Chinese breed Meishan, and the European Wild Boar. Each individual was genotyped for 20 selected polymorphic microsatellite loci. The Vietnamese autochthonous breeds showed higher degrees of polymorphism, allelic diversity, and heterozygosity than the other pig breeds. Also, large genetic diversity was observed across the area of distribution, with village-specific subpopulations, which led to significant inbreeding coefficients. As expected, genetic distances showed large differences among European-based, Chinese, and Vietnamese indigenous breeds and reflected the geographical distribution of breeds. In comparison with the European breeds, the Vietnamese indigenous pig breeds harbored a considerable amount of genetic diversity and, therefore, will be of significance for livestock bioconservation.     

Anti-Inflammatory Components of the Starfish Astropecten polyacanthus

Inflammation is important in biomedical research, because it plays a key role in inflammatory diseases including rheumatoid arthritis and other forms of arthritis, diabetes, heart disease, irritable bowel syndrome, Alzheimer’s disease, Parkinson’s disease, allergies, asthma, and even cancer. In the present study, we describe the inhibitory effect of crude extracts and steroids isolated from the starfish Astropecten polyacanthus on pro-inflammatory cytokine (Interleukin-12 (IL-12) p40, interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α)) production in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs). Among those tested, compounds 5 and 7 showed potent inhibitory effects on the production of all three pro-inflammatory cytokines with IC₅₀ values ranging from 1.82 ± 0.11 to 7.00 ± 0.16 μM. Potent inhibitory activities were also observed for compound 1 on the production of IL-12 p40 and IL-6 with values of 3.96 ± 0.12 and 4.07 ± 0.13 μM, respectively, and for compounds 3 and 4 on the production of IL-12 p40 with values of 6.55 ± 0.18 and 5.06 ± 0.16 μM, respectively. Moreover, compounds 2 (IC₅₀ = 34.86 ± 0.31 μM) and 6 (IC₅₀ = 79.05 ± 2.05 μM) exhibited moderate inhibitory effects on the production of IL-12 p40, whereas compounds 3 (IC₅₀ = 22.80 ± 0.21 μM) and 4 (IC₅₀ = 16.73 ± 0.25 μM) moderately inhibited the production of TNF-α and IL-6, respectively.     

农用柔性底盘偏置轴转向机构联动耦合控制策略及试验

针对农用柔性底盘前轮转向时两偏置轴转向机构难以保持联动关系而影响顺利转弯的问题,基于阿克曼转向几何与交叉耦合控制原理,设计了偏置轴转向机构联动耦合控制策略,采用模糊PID控制算法对两转向轮转角联动轮廓误差进行补偿,并依据方向盘信号大小和变化率对电磁摩擦锁PWM控制信号占空比进行调节,以匹配偏置电动轮转向的角速度,使两转向机构形成耦合而保持期望联动关系;基于MATLAB/Simulink对控制策略进行了仿真,且在硬化路面上实施了阶跃转向、蛇行转向及随机转向3种运动方式的试验验证,并对比分析了转角分配控制下的前轮转向效果。试验结果表明:耦合控制方法下柔性底盘前轮阶跃转向响应均在0.8 s内,左、右侧转角最大超调为1.3°;电磁摩擦锁的开闭可较好匹配电动轮的转向;左、右前轮对于各自目标角具有良好的跟踪性能;3种转向方式下最大与平均跟随误差值均小于分配控制方法;两轮联动的最大与平均转角轮廓误差分别为:阶跃转向1.2°与0.6°、蛇行转向1.1°与0.6°、随机转向1.0°与0.5°;耦合控制下仿真与试验转角的轮廓误差变化趋势一致,最大误差为2.2°,证明仿真模型合理有效。耦合控制下偏置轴转向机构联动控制效果优于转角分配控制,转向效果良好,该文提出的柔性底盘偏置轴转向机构联动耦合控制策略有效且可行。     

Assessment of household risk management strategies for coastal aquaculture: the case of clam farming in Thaibinh Province,Vietnam

Clam farmers have experienced different types of risks that have been further exacerbated by the rapid expansion of clam farming areas, increased growing densities, and increased market difficulties in recent years in the Thaibinh Province of Vietnam. Most farmers have been seriously affected by production risk, market risk, and financial risk, while a number of others have met with success in almost all of their clam-raising cycles. This study applied a differentiating comparative analysis method and multiple discriminant analysis method to discuss the differences in risk management strategies between and among clam farming households and the impacts of those differences on their success/failure rates. In general, the tactics are related to increase in farm size, the application of technical innovations, diversifying livelihood activities, and accessing secure financial sources all provided better conditions for clam growth, diminished losses, and led to speedier recovery from shocks. To support farmers in managing risks, several government interventions are needed: (1) better re-zoning of clam farming areas in parallel with an increase in the farm size of each household, (2) promoting sustainable linkages between the farmers and the formal financial market and output market, and (3) investing more funding into research and extension related to sustainable clam farming practices and to the improvement of farmers’ skills in cooperative works and management.