The term “cholov stam” does not exist in halocho, and certainly Reb Moshe never uses it.
That is my understanding as well; the term used by HaRav Hagaon Rav Moshe Feinstein, ZT”L, in Igros Moshe is <i>Kholov ‘HaCompanies'</i>.
When discussing this topic of whether milk produced under government inspection is permissable, it must be noted that (at least in the U.S.; I am unfamiliar with the <i>metzius</i> elsewhere) the shailo <i>today</i> is not only one of a <i>d’rabbonan</i> but also of a <i>d’oraisa</i> of <i>treifus</i>> (This is because of a change in <i>metzius</i> since the time of the Igros Moshe. Namely, the surgeries that are routinely performed on dairy cows.) Thus, even many of those who had previously relied upon the <i>heter</i> to use commercially produced (but non-<i>kholov Yisroel</i>) milk no longer do so today. As always, one should consult his <i>poseik</i>/<i>morah derekh</i> for guidance.