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91.
收益共享契约是实现供应链系统绩效改善或完美协调的一种机制.考虑了零售商与供应商分别具有风险厌恶决策偏好情况下,在随机市场需求下建立了由单供应商和单零售商组成的二级供应链的收益共享契约模型,并对模型进行了分析,揭示了供应商和零售商的风险厌恶决策偏好对收益共享契约参数的影响.研究结果表明:当销售商(供应商)的风险厌恶控制在一定程度内时,通过调整收益共享契约参数,可以保证供应链的协调. 相似文献
92.
天气衍生品是为了规避天气风险给天气敏感行业带来收入的不稳定性而兴起的创新型风险管理工具,其实质是通过衍生合约对天气风险进行分割、重组和交易的证券化产品。不同于传统金融衍生品,天气衍生品的价值取决于温度、湿度或降雨量等天气指数。本文在分析天气衍生品市场发展的基础上,重点探讨了最常见的天气期货和天气期权的运作机制及其精算定价。 相似文献
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综合干旱类型,从致灾因子的危险性、敏感性、易损性及防灾减灾能力4个指标出发,分析气候变化背景下的山东省济南市长清区干旱灾害风险变化。结果表明,长清区干旱危险性分布特征总体表现为由西北向东南递减的趋势;干旱灾害孕灾体敏感性总体呈现出由西南向东北递减的趋势;干旱灾害易损性分布基本以行政区为单位,高易损性分布在除平安街道办事处外的西部地区;干旱灾害的防灾减灾能力总体呈现东北高、西南低的分布特征;干旱综合风险性呈现西南高、东北低的分布规律。 相似文献
94.
Florida strawberry farmers usually rely on weekly calendar fungicide applications to prevent yield loss from Botrytis fruit rot (BFR). The Strawberry Advisory System (SAS), which helps optimize the timing of fungicide applications, is an additional tool in the farmers' arsenal of disease control options. This study uses data from two-year production trials in Florida combined with historical strawberry prices to measure the economic performance of the Calendar and SAS-based BFR management practices under output price risk and producers' risk preferences. We use Monte Carlo simulation to model the effect of the variability in weekly output prices on farm returns. Results reveal that the traditional calendar-based system is not the least risky BFR management option as growers expected to be. SAS-based options such as SAS-Switch and SAS-Luna would be preferred by both risk-neutral and risk-averse producers and are recommended under high disease pressure conditions. 相似文献
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Ibrahim Bala Salisu Ahmad Ali Shahid Amina Yaqoob Ambreen Gul Abdul Qayyum Rao 《Journal of animal physiology and animal nutrition》2021,105(2):354-363
Recent studies have demonstrated a strong relationship between the intestinal microbiota and the host health. As such, consumers are increasingly becoming more concerned about the potential effect of certain foods/feeds, particularly of transgenic origin on the gut microbiota. Although the European Food Safety Authority has recommended in their guidelines, to study the effect of transgenic food/feed on host-microbiota, yet, few studies have focused on the evaluation of such effects mainly due to culturing difficulties. Therefore, this study was intended to evaluate the potential adverse effects of transgenic diet consumption on some specific gut microflora (Lactobacillus group, Bifidobacterium genus, Escherichia coli subgroup and Enterococcus genus) of rabbits. A total of forty-eight rabbits were randomly assigned into four groups and fed a diet containing a variable proportion of transgenic cottonseeds at 0, 20, 30 and 40% inclusion level, respectively. Changes in the specific or total faecal bacterial population were monitored at five different experimental stages (i.e. 0, 45, 90, 135 and 180 days) using both the traditional plate count method (TM) and quantitative real-time PCR (qPCR). No significant differences (p > .05) were observed concerning numbers of specific bacteria or total bacteria between the control and experimental groups, though qPCR showed numerically higher values in terms of 16S rRNA gene copies as compared to the values obtained from TM. However, such numerical differences were biologically insignificant (p > .05). Similarly, no significant variations were noticed in the calculated B/E (log10 copies of Bifidobacterium per g faces/log10 copies of E. coli genome per g faeces) ratios in all the groups. All the ratios were in the range of 1.24 to 1.30 throughout the experiment, indicating a good balance of intestinal microflora and greater resistance to intestinal disorders. It is therefore concluded that feeding transgenic cottonseeds could not adversely affect the gut microflora of rabbits during a long-term study. 相似文献
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Sara Bellezza Oddon Ilaria Biasato Arianna Imarisio Miha Pipan Dominik Dekleva Elena Colombino Maria Teresa Capucchio Marco Meneguz Stefania Bergagna Raffaella Barbero Marta Gariglio Sihem Dabbou Edoardo Fiorilla Laura Gasco Achille Schiavone 《Journal of animal physiology and animal nutrition》2021,105(Z1):10-18
The commercial broiler chicken strains are the result of successful selection programmes. Most of the problems related to welfare arise from the high growth rate and body weight. The use of environmental enrichments in intensive farming could have a positive effect on birds by increasing animal welfare. The aim of the study was to evaluate the effects of Hermetia illucens (HI) and Tenebrio molitor (TM) live larvae in the diets of broiler chickens on growth performance, carcass yield and health status. A total of 180 four-day-old male broiler chickens (Ross 308) were randomly allotted to 18 pens. Each pen was assigned to one of the three dietary treatments (6 replicates/treatment, 10 birds/replicate) as follows: (i) control diet (C): commercial feed (two feeding phases: starter [4–11 days] and grower [12–38 days]), (ii) HI: C + 5% of the expected daily feed intake (DFI) HI live larvae (calculated on dry matter [DM]) and (iii) TM: C + 5% of DFI TM live larvae (DM). At 39 days of age, birds were slaughtered. Growth performance parameters were overall not affected by dietary treatments, except for the grower phase feed conversion ratio (FCR) and the overall FCR being better in the TM broilers than the others (p < 0.01). No differences were observed for slaughtering performance and haematological and serum parameters, except for the spleen relative weight being higher (p < 0.01) in the birds administered with larvae when compared to the C group. Gut morphometric indexes and histopathological alterations were not influenced by insect larvae administration. In conclusion, the administration in limited quantities of HI and TM live larvae as environmental enrichment has no negative effects on broiler chicken growth performance and health status. A behavioural study could confirm that live insect larvae represent a novel natural environmental enrichment in broiler farming. 相似文献
100.
在我国养猪业面临产品安全和环境污染两大瓶颈的情势下,如何使所生产的猪肉食用卫生,所排粪污环境安全,纯天然、无污染、广效低毒、绿色环保的中兽医药学为破解这两大瓶颈提供了技术支撑。充分发挥我国传统的中兽医药技术的特色和优势,构建以中兽医药为主体的猪只康养技术供给体系,旨在集生产管理"适其天性"、所喂药料"无污染"、治疗药物"纯天然"、预防措施治"未病"、治疗方法"和谐调节"和四季保健"药饲同源"于一体的技术供给体系,从源头上破解这两大难题,从而实现猪只康养,环境安全,猪肉安康,凸显出中兽医药是猪只康养的最佳供给体系。 相似文献