there was much ado about chlorinated chicken a few days ago. apparently the US washes chicken carcasses with chlorine to disinfect them, whereas that's illegal in the EU, which has more stringent farm cleanliness standards instead. I think there's similar issues with an arsenic compound (seriously!) being fed to chicken as some sort of antibiotic.
iirc Trump did say he wanted EU to accept our livestock to reduce the trade deficit, leading Lutnick to memorably proclaim "They hate our beef because our beef is beautiful and theirs is weak!"
"Chlorinated chicken" has been a discussion topic in Britain since before Brexit, when some politicians were saying it would be easy to get a deal with the USA to replace trade with the EU.
It's not something that will be forgotten easily. British people on all sides were against reducing food standards.
IMO I think we'll end up with "a uk body setting new GMO standards" being cover to allow US GMO stuff in. Then maybe hormone beef and similar, but not chicken. Quota-less fish, tariff free trucks/cars (like that's going to make a difference) and some other minor tweaks.
iirc Trump did say he wanted EU to accept our livestock to reduce the trade deficit, leading Lutnick to memorably proclaim "They hate our beef because our beef is beautiful and theirs is weak!"