Terry D. Etherton is the Department Head and Distinguished Professor of Animal Nutrition at Penn State University. He writes on a Dairy and Animal Science Blog, frequently discussing Eli Lilly's recombinant bovine growth hormone (owned by Monsanto until August 2008). Etherton is strongly pro-rBGH and argues strongly for its use, including denying any difference in milk from cows treated with rBGH compared to milk from untreated cows.
Critics of the Vicini and Etherton study claiming a lack of difference in milk with three labels (conventional, rBGH-free, and organic) cite that dairies that accept milk from cows treated with rBGH would not segregate milk from treated cows from rBGH-free milk, so the conventional milk used in the study was probably mostly rBGH-free. Also note that Monsanto funded this study, Monsanto staff collected the samples, and it was written mostly by Monsanto employees, along with Terry Etherton, who has been funded by Monsanto, and his wife. Furthermore, the analysis for IGF-1 was conducted by Monsanto instead of by an independent lab. (The study also states that IGF-1 degrades in the digestive tract, but that is not true when casein is present.)