中文摘要：

在主流的“公司（奶站）＋奶农”的原奶供应链中，原奶质量安全受到三个变量的影响：收购价格、检测成本和高质量原奶的生产成本。这三个变量与原奶供给质量的关系是：收购价格越高、检测成本和高质量成本越低，则原奶质量越高。在当前公司与奶农的简单商品契约交易下．三个质量影响变量难以向着高质量原奶的方向发生变动，因此原奶的供给陷入了低质量均衡。以公司与奶农的简单交易为基础，并附加质量管理输出等内容的超市场契约模式下，三个影响变量的变动方向将与高质量原奶的要求相一致。

英文摘要：

There are three variables in the main supply chain of raw milk--＂corporation （milk station ） ＋dairy farmer＂： procurement price, inspection cost and production cost of high quality raw milk. The higher the procurement price is, and the lower the inspection cost and the cost of high quality raw milk are, the higher the quality of raw milk is. Currently, under the simple commodity contract between the corporation and dairy farmer, the change of three variables goes against the quality enhancement of raw milk, so that the raw milk is caught in a low quality trap. The super market contract with quality control provisions annexed can prompt the three variables to change towards the high quality.