This work estimates Probit and Tobit models of the adoption of rbST on Connecticut dairy farms and then endogenizes that adoption in estimates of milk production and farm profit rates. The work improves on the current literature by allowing the rbST decision to be both continuous and contingent on other technology adoption decisions. The results show that larger farms, with more productivity technologies, and with younger, more educated farmers are more likely to adopt rbST. While rbST is shown to significantly increase milk production there is no evidence it increases profits on a per cow basis.