Nafi' (may Allah have mercy on him) said that Abdullah bin Umar (may Allah be pleased with them both) would not tear the coverings of his sacrificial camels, nor would he put the coverings on them until the morning he set out from Mina towards Arafah. Others added to it: except at the place of the hump; and when he slaughtered them, he would remove their coverings for fear that the blood would spoil them, then give them in charity.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10187