if has("mac")
	map <silent> sY :call YankPB()<CR>
	function! YankPB()
		let tmp = tempname()
		call writefile(getline(a:firstline, a:lastline), tmp, 'b')
		silent exec ":!cat " . tmp . " | pbcopy"
	endfunction
endif

してみた

export __CF_USER_TEXT_ENCODING='0x1F5:0x08000100:14'