If one is not makpid on Cholov Yisroel in the USA, based on R' Moshe Feinstein ZT"L's p'sak, would the same reasoning apply to milk in European countries, including Spain? I know that his famous pasak only covered the USA at the time, and did not address other countries, but should the same rationale apply elsewhere nowadays where there is government regulation and inspections and negative economic repercussions for companies to deviate?
The following facts may also be relevant: While the economics involved may have changed over time, according to Wikipedia, quoted below, currently, pig's milk is not a viable agricultural product for human consumption:
"Difficulty in milking pigs. Pig milk is not considered suitable for human consumption or commercial production for a number of reasons. Pigs are considered difficult to milk. The sow herself is reluctant to be milked, may be uncooperative or become spooked by human presence, and lactating pigs may be quite aggressive. Sows have 8 to 16 small nipples, each giving little milk for a short duration. A cow's milking time can be around ten minutes compared to fifteen seconds for a pig. A sow may produce only 13 pounds of milk per day compared to a cow's production of 65 pounds. (Production has been estimated using a system of weighing piglets prior to and after suckling.) In addition, no existing milking machine is designed to attach to around a dozen teats and extract milk for fifteen seconds. Finally, pigs, unlike cows, cannot become pregnant while lactating, which makes a pig milk operation even less viable."
"Human uses. Pig milk is generally considered unappealing for human consumption. Compared to more conventional animals such as dairy cattle or goats, a main issue is their cleanliness and diet. Also, the flavor of pig milk has been described as "gamy", more so than goat's milk. The milk is also considered more watery than cow's milk."
See also:
https://onpasture.com/2015/01/05/why-dont-we-drink-pig-milk/