This chapter provides information about potential impacts of Bovine somatotropin (BST) has led to research which estimates the rate of adoption among dairy farms. It discusses factors affecting technology adoption and the role of technological change in the dairy industry over the years. Factors positively correlated with rapid adoption were herd size and the use of artificial insemination, while output per cow and use of freestall housing were negatively correlated with rapid adoption. L. Zepeda used the same data in a technology-adoption model to test hypotheses about BST adoption and forecast adoption patterns in California. The few early agricultural press reports of BST were based on data from a limited number of small-scale research trials, and indicated that commercial availability was years away. Awareness of BST among dairy farm managers was low, with 50 percent reporting not having heard of the technology before the survey.