What are the rules for animal sacrifice during Haji?

The animal sacrifice (hadyu) is wajib (wajib) for jamaah haji performing Haji Tamattu (those who perform Umrah, exit Ihram, then enter Ihram again for Haji) and Haji Qiran (those who combine Umrah and Haji in a single Ihram). Pilgrims performing Haji Ifrad (Haji only, without Umrah) are not required to offer a sacrifice, though it is sunnah.

Acceptable animals include: a sheep or goat (one per jamaah haji), a cow (shared among up to 7 jamaah haji), or a camel (shared among up to 7 jamaah haji). The animal must meet minimum age requirements — sheep must be at least 6 months old, goats 1 year, cows 2 years, and camels 5 years. The animal should be healthy and free from defects: not blind in one eye, not obviously lame, not emaciated, and not missing a significant portion of an ear or horn.

The sacrifice should ideally be performed on the 10th of Dzulhijjah (Yawm al-Nahr — Day of Sacrifice), as part of the day's sequence: stoning, then sacrifice, then shaving/trimming, then Tawaf. However, the sacrifice may be delayed until before sunset on the 13th of Dzulhijjah. Most jamaah haji today arrange their sacrifice through the Saudi Project for Utilization of Hady and Udhiyah (the official sacrifice management organization), which handles the slaughter and distributes the meat to the poor worldwide. You simply pay the fee and receive a certificate confirming the sacrifice was performed.