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631.
We aimed to determine the effects of nutritional status on concentrations of somatotropic axis hormones (growth hormone (GH) and insulin‐like growth factor 1 (IGF‐1)), insulin and metabolites (glucose, total protein and nonesterified fatty acids (NEFA)) in the plasma and colostrum in late antepartum cows. Eight pregnant Japanese Black cows were randomly assigned to two experimental groups (n = 4 per group). Control cows (CON) received 100% of their nutritional requirements until parturition, whereas restricted group cows (RES) received 60% of their nutritional requirements. Blood samples were taken during the antepartum period, and blood and colostrum samples were collected on days 0, 1, and 3 after calving. Compared to the CON group, the RES group had higher concentrations of GH and NEFA in plasma, but significantly lower concentrations of glucose and insulin in plasma. The concentrations of GH in plasma after calving were significantly higher, but total plasma protein was significantly lower in RES than in CON cows. Compared to the CON group, the RES group had significantly higher concentrations of GH in colostrum, but significantly lower total concentrations of protein in colostrum. Concentrations of IGF‐1 were not different between the two groups. These findings suggest that maternal nutritional status during late gestation influences concentrations of GH and total protein in the blood and colostrum of Japanese Black cows.  相似文献   
632.
Catalytic oxidation of benzene, toluene, and ethylbenzene (BTE) on virgin zeolite, nZnO-coated zeolite, with and without UV?+?O3, at 300 °C bed temperature was investigated using laboratory experiments. The coating was done at three weight ratios of Zn (estimated Zn content in nZnO) to zeolite (0.2:1.0, 0.5:10, 1.0:1.0). The coated adsorbents were examined by scanning electron microscopy, wavelength dispersive X-ray spectroscopy, and Brunauer Emmett Teller analyses. In the catalytic oxidation experiments, the adsorbents were first saturated with BTE by purging an air stream containing a mixture of BTE at 5 ppm each for 28 min. Introduction of UV?+?O3 on the coated 13X zeolite (0.5:1.0) bed improved the average removal efficiency (RE) of benzene, toluene, and ethylbenzene (with inlet concentration of 5 ppm each) to 68.7, 90.0, and 99.6%, respectively, from the corresponding values of 57.3, 79.9, and 98.5% when no UV?+?O3 was used. An increase in the coating weight ratio from 0.2:1.0 to 0.5:1.0 had produced a higher RE for benzene only, while a further increase to 1.0:1.0 witnessed a decrease in RE for all three compounds, and more for benzene. Avg RE of BTE decreased with the increase in their inlet concentrations, more significantly for an increase from 5 to 50 ppm and less noticeable for a further increase to 100 ppm. The final oxidation products and intermediate products in the outlet streams from the oxidation and thermal desorption were analyzed which showed predominant compositions of CO2 followed by BTE and some levels of CO and other volatile organic compounds.  相似文献   
633.
Agroforestry is known to have multiple economic and environmental benefits. Despite this, the adoption of agroforestry in Viet Nam is limited both in extent and diversity of components and practices. Our study identified gaps for agroforestry adoption in current policies and policy implementation. National policy and provincial instructions and decisions were reviewed and discussed during ten stakeholders’ consultation workshops. The review and workshops concluded that there were no specific national and few provincial specific policies promoting agroforestry. In addition, the segregation of policies into agriculture and forestry, promoted monoculture practices and discouraged the integration of mixed annual and perennial tree species. Completing the forestland allocation process was considered essential for long-term investment on land and providing collateral for loans. More holistic policies, such as a provincial strategy for agroforestry development that would enable flexible integration of agriculture, forestry and livestock were perceived to be more effective and inclusive to poor and non-poor farmers. Specific cross-cutting budget allocation would be necessary for capacity building, upscaling agroforestry models, procurement of high-quality inputs, and establishing post-harvest processing and marketing investments.  相似文献   
634.
Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non‐monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non‐monetary benefit) which was mainly obtained from other private actors and media.  相似文献   
635.
α-Amylase inhibitors (aAIs) have been applied for the efficient management of type 2 diabetes. The aim of this study was to search for potential aAIs produced by microbial fermentation. Among various bacterial strains, Pseudomonas aeruginosa TUN03 was found to be a potential aAI-producing strain, and shrimp heads powder (SHP) was screened as the most suitable C/N source for fermentation. P. aeruginosa TUN03 exhibited the highest aAIs productivity (3100 U/mL) in the medium containing 1.5% SHP with an initial pH of 7–7.5, and fermentation was performed at 27.5 °C for two days. Further, aAI compounds were investigated for scaled-up production in a 14 L-bioreactor system. The results revealed a high yield (4200 U/mL) in a much shorter fermentation time (12 h) compared to fermentation in flasks. Bioactivity-guided purification resulted in the isolation of one major target compound, identified as hemi-pyocyanin (HPC) via gas chromatography-mass spectrometry and nuclear magnetic resonance. Its purity was analyzed by high-performance liquid chromatography. HPC demonstrated potent α-amylase inhibitory activity comparable to that of acarbose, a commercial antidiabetic drug. Notably, HPC was determined as a new aAI. The docking study indicated that HPC inhibits α-amylase by binding to amino acid Arg421 at the biding site on enzyme α-amylase with good binding energy (−9.3 kcal/mol) and creating two linkages of H-acceptors.  相似文献   
636.

Shrimp aquaculture is the biggest source of export income in Vietnam. However, the development of the shrimp poses a serious threat to coastal mangroves by converting coastal mangroves into shrimp farms. Much effort has been made to replant mangroves and reduce the impacts of shrimp farming on the environment, and maintaining mangrove coverage at 30–50% of total farm area has provided the highest benefits in the integrated mangrove shrimp model. In this study, we re-examine the benefits of forest cover on the survival and yield of tiger shrimp (Penaeus monodon) in the integrated mangrove shrimp farming systems in Ca Mau province, Vietnam. The study found positive linear correlations of log transformed survival and yield of tiger shrimp with forest cover of the forms: Ln (survival)?=????1.39?+?0.038?×?forest coverage (r2?=?0.22; p value?=?0.0007); Ln (yield)?=?3.55?+?0.026?×?forest coverage (r2?=?0.16; p value?=?0.004). The households with high forest cover (i.e.,?>?45%) also had 1.07?±?0.29 and 1.39?±?0.36 (CI 95%, p value?=?0.000) kg ha?1 higher yield per night harvest than those with medium and low forest cover, respectively. As a result, households with high forest cover have higher benefits than those with lower forest cover. Our findings together with previous published studies lead to the recommendation that farmers maintain mangroves in farming systems for better economic and environmental benefits.

  相似文献   
637.
饲料中添加纤维素酶对团头鲂生长的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
在 A、B、C、C0 和 D五组团头鲂鱼种 (体均重 2 .35± 0 .2 0 g)的配合饲料中分别加 0、6 0 0、2 4 0 0、2 4 0 0和 4 2 0 0 U/ kg纤维素酶。其中 B、C、D组中加入的纤维素酶都经过适当的预处理 ,而 C0 组饲料则直接添加 2 4 0 0 U/ kg的纤维素酶。经 56天喂养试验 ,结果显示 :投喂 B、C两组饲料的鱼体增重率分别比 A组提高了 14 .59%和 34.18% ,饲料效率也分别提高 6 .0 6 %和13.6 4 % ;而 C0 和 D组的生长性能则与 A组之间没有显著性差异。  相似文献   
638.
为了掌握植物物候期标指性气候特征,本文依据农八师垦区自然物候和气象观测资料,利用线性回归、相关分析、Mann-Kendall突变检验等方法,研究了该地区1980—2018年木本植物旱柳、榆树、箭杆杨春季物候特征及其对气温变化的响应规律。结果表明:旱柳、榆树、箭杆杨春季物候期提前趋势明显。旱柳展叶始期、开花盛期平均每10年提前2.9天和2.7天,2004年突变之后平均提前了4~5天。榆树展叶始期、开花盛期平均每10年提前5.6天和1.3天,2004年突变之后平均提前了9天和5天。箭杆杨展叶期平均每10年提前2.7天,2004年突变之后平均提前了4天。3—4月平均气温与旱柳、榆树、箭杆杨春季物候期呈显著负相关,在物候期之前1~2个月(3、4月份)内气温对木本物候期的影响最为显著。研究区当3—4月平均气温每上升1℃时,旱柳展叶始期、开花盛期分别提前1.8天;榆树展叶始期、开花盛期分别提前2.9天和1.8天;箭杆杨展叶始期提前1.9天。综上诉述,研究区气候变暖木本植物春季物候期提前已成为事实,这对于农时预报服务于当地农业生产起到良好作用,研究结果可为当地生态系统保护、农业结构调整及旅游产业开发等提供参考。  相似文献   
639.
A study was conducted with Hy-Line Brown laying hens to examine the effects of reduced protein diet, deficiency of arginine (Arg), and addition of crystalline Arg, citrulline (Cit) and guanidinoacetic acid (GAA) as substitutes for Arg. Hen performance, egg quality, serum uric acid, liver and reproductive organ weights, and energy and protein digestibility were measured using a completely randomized design with 5 treatments. Treatments were a standard diet (17% protein diet; SP), a reduced diet (13% protein diet deficient in Arg; RP) and RP with added Arg (0.35%, RP-Arg), GAA (0.46% equivalent to 0.35% Arg, RP-GAA) or Cit (0.35%, RP-Cit) to the level of SP. It was hypothesized that performance would decrease with Arg deficient RP diet and the addition of GAA or Cit in RP would allow birds to perform similar or greater than Arg-added RP treatment. The experiment was conducted from 20 to 39 wk of age but the treatment effect was seen only after 29 wk of age. The birds offered RP had reduced egg and albumin weights (P < 0.01), lower yolk color score (P < 0.01), lower protein intake and excretion (P < 0.01) than those offered SP. When Arg or Cit were added to RP to make them equivalent to SP, feed intake (FI) and egg production were not different than those of RP (P > 0.05). The birds offered RP-GAA decreased FI and egg production (P < 0.01) compared to those offered RP. The addition of Arg, Cit or GAA to the RP had no effect on egg quality parameters, protein and energy digestibilities (P > 0.05). However, birds offered the RP-Cit diet tended to have higher Haugh unit (P = 0.095) and lower shell breaking strength (P = 0.088) compared to all other treatments while those offered RP-GAA had higher energy digestibility (P < 0.05) than all other groups but RP. The limited performance response of hens fed RP with added Arg, GAA, or Cit may be due to deficiency of some other nutrients in RP such as phenylalanine, potassium or non-essential amino acids and other components of soybean meal in the diet.  相似文献   
640.
Genetic Resources and Crop Evolution - Collection and storage of crop wild relative (CWR) germplasm is crucial for preserving species genetic diversity and crop improvement. Nevertheless, much of...  相似文献   
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