Cholov Yisroel - Commercial milk in America

 Igros Moshe (YD I #47) Commercial milk in America In general milk needs to be supervised by Jews to be regarded as fully kosher.  So regarding the kashrus of commercial milk in America which while not being supervised by Jews nonetheless has a government inspector and anyone who adds the milk of an unclean animal will be punished and will also their business will be closed. Consequently the companies are definitely afraid to mix unkosher milk in the kosher milk and that is a major reason to permit as kosher their milk even according to the view of the Pri Chodesh even though there is no actual Jewish supervision.  Since a clear awareness of the consequences is the same as being watched as is stated in the gemora Shavuos regarding monetary issues. An additional proof can be found in Tosfos (Yevamos) concerning the requirement that conversion requires the direct watching by beis din of the immersion of the ger in a mikveh and it says that common knowledge is considered actually observing. This is the well known concept known as Anon Sahadi. Even in the case of witnesses for a marriage, even if they didn’t actually witness the event but only that the couple were secluded together, it is considered as if they actually witnessed the intercourse and the couple is halachacly married. And they would even get the death penalty if they are involved in an adulterous relationship afterwards and they are not allowed to marry someone else. Another case is the principle that a person is assumed not to be involved in fornication and this is treated as actually witnessing in order to validate a marriage even for a liency of not requiring a Get in the case of a child without miyun who is now an adult and she married another person.  There is also the case of adultery in which the witnesses do not have to see the actual intercourse but we rely on circumstantial evidence.  This is also the case for the crime of murder and other capital crimes that we rely on circumstantial evidence.  From all these cases we can conclude that knowledge is considered seeing even for the death penalty except where there is a derasha which requires actually witnessing an event. Consequently in the case of milk which is prohibited if a Jew has not watched it, it should be considered kosher simply by the clear awareness that a Jew has that is considered as witnessing  The awareness that if the milk is mixed with unkosher milk the company will be punished and the business will be closed and they will endup losing a lot of money and that the government is supervising them, this is clearly awareness and is considered as actually witnessing and there is no prohibition according to everyone. .Therefore, there is a major justification for someone to rely on this leniency and it is fitting as in fact the majority of religious Jews and also many rabbis in fact do. G-d forbid to claim that this is against the halacha!. Nevertheless a baal nefesh should be strict and not rely on this leniency and ir is nor viewed as sinful pride. I myself am strict not to rely on it. However all those not restrained by a neder derived from custom if they wish to utilize this leniency is not considered ridiculing prohibitions. .A person who was strict 3 times it constitutes a neder unless he was strict only because he thought he was required to by halacha. He does not have to annul the mistaken neder