Yahya related to me from Malik from Abu'z-Zinad that Said ibn al-Musayyab said, "Bartering live animals for dead meat is forbidden."Abu'z-Zinad said, "I said to Said ibn Musayyab, 'What do you think ofa man buying an old camel for 10 sheep?' " Said said, "If he buys itto slaughter it, there is no good in it." Abu'z-Zinad added, "All thepeople (i.e. companions) that I have seen forbade bartering liveanimals for meat."Abu'z-Zinad said, "This used to be writtenin the appointment letters of governors in the time of Aban ibn Uthmanand Hisham ibn Ismail."
USC-MSA web (English) reference: Book 31, Hadith 66
Arabic reference: Book 31, Hadith 1358