Aquaculture Drug Reduction Decision Considering Supply Chain Structure

Adverse events caused by excessive and indiscriminate drug use occur frequently in aquaculture,and drug safety has become a non-negligible problem in the current aquaculture process.Reducing the use of drugs in aquaculture is an inevitable requirement to promote the high-quality development of aquatic products,which is of great significance to guarantee the people’s vegetable basket and protect the safety of the people’s table.For this reason,the government must intervene and control the phenomenon of indiscriminate drug use.The organization form of "farmer + enterprise" accounts for more than 80% of the industry,which is the main order agriculture mode,while the organization form of "farmer + cooperative + enterprise" is an important part of agricultural modernization.Therefore,this thesis carries out research on the above two industrial forms.First of all,with the supply chain structure of "farmer + enterprise" as the background,A two-stage Stackelberg game model is constructed based on deterministic output and stochastic output.Farmers’ drug reduction decisions under wholesale price contract(wp)and revenue sharing contract(rs)were investigated respectively.It also makes a comparative study of the decision and profit under different contracts and different demand structures.The model is further extended to supply chain structure composed of multiple farmers and one company to explore the influence of competition factors on drug reduction decisions.Secondly,with the supply chain structure of "farmer + cooperative + enterprise" as the background,the generalized Nash bargaining model was constructed based on deterministic output and stochastic output respectively,and the drug reduction decisions of farmers under sales revenue agency contract(os)and drug reduction subsidy and sales revenue sharing contract(bs)were investigated respectively.It also makes a comparative study of the decision-making and income under different contracts and different demand structures.The model is further extended to supply chain structure composed of multiple farmers and one company to explore the influence of competition factors on drug reduction decisions.The results show that :(1)In the two-level supply chain of "farmer + company",revenue sharing contract(rs)can effectively promote green aquaculture;In the three-level supply chain of "farmer + cooperative + enterprise",the sales revenue agency contract(os)can effectively promote green aquaculture.(2)Drug reduction decision under stochastic output is not affected by supply chain structure and contract selection.The higher the expected output rate,the greater the profit of supply chain members,the less drug use.Keeping a stable yield rate can promote the smooth development of drug reduction action.(3)The greater the level of subsidies,the motivation of supply chain members to reduce drugs does not necessarily increase.The government should comprehensively collect information of farmers and product demand elasticity,and set reasonable government subsidies for units exceeding the threshold value to encourage supply chain members to reduce drug use.(4)Multiple farmers carry out market competition is conducive to reduce the drug consumption of farmers and promote the healthy development of the industry.Therefore,the study of this thesis has important guiding significance for reducing drug use in aquaculture and promoting green aquaculture.