Miller G Y, McSweeny W T
Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus 43210.
J Am Vet Med Assoc. 1993 Jan 15;202(2):220-6.
The value of the marginal product (VMP) for veterinary services and medical supplies (VETMED), and the profit maximizing level of VETMED were estimated for dairy producers. Data from the Pennsylvania Farmers Association-Dairy Farm Business Analysis system during the years of 1986 to 1990 were used to evaluate the functional relationship between production and expenditures for VETMED. Other input variables examined were man-year equivalents of labor, asset values, value of feed fed, and culling rate. Data were screened to reflect economically viable dairy farms in Pennsylvania, and 173 such farms participated for each of the 5 years analyzed. The VMP was estimated for 1990. Profit maximizing levels for VETMED were estimated for 1990 holding other input variables at their mean values. Mean expenditures for VETMED were $2,606/farm, or $43/cow in 1990. The VMP for VETMED was estimated to be $3.22 or $4.98, depending on the method of calculation. In other words, the marginal dollar spent on VETMED generated $3.22 ($4.98) in additional revenue from milk production. The profit maximizing level of expenditures for VETMED was $138/cow, substantially more than the mean, indicating the potential for farms in this data set to improve profitability through additional expenditures on VETMED.
研究估算了乳制品生产商的兽医服务和医疗用品（VETMED）的边际产品价值（VMP）以及VETMED的利润最大化水平。利用宾夕法尼亚农民协会-奶牛场商业分析系统在1986年至1990年期间的数据，评估了VETMED的生产与支出之间的函数关系。所考察的其他投入变量包括人工年当量的劳动力、资产价值、所投喂饲料的价值以及淘汰率。对数据进行筛选以反映宾夕法尼亚州经济上可行的奶牛场，在分析的5年中，每年都有173个这样的农场参与。估算了1990年的VMP。在其他投入变量保持在其平均值的情况下，估算了1990年VETMED的利润最大化水平。1990年，VETMED的平均支出为每个农场2606美元，即每头奶牛43美元。根据计算方法的不同，VETMED的VMP估计为3.22美元或4.98美元。换句话说，花在VETMED上的边际美元能从牛奶生产中产生3.22美元（4.98美元）的额外收入。VETMED的利润最大化支出水平为每头奶牛138美元，大大高于平均水平，这表明该数据集中的农场有通过增加VETMED支出来提高盈利能力的潜力。
