Conditions of  Udh-hiyah:

There are conditions for the Udh-hiyah in order to be valid and accepted:

* The first condition: It should be of camels, cows, sheep and goats. Allaah The Exalted Says (what means): {And for all religion We Have Appointed a rite [of sacrifice] that they may mention the name of Allaah over what He Has Provided for them of [sacrificial] animals.} [Quran 22: 34] In a Hadeeth, the Prophet, sallallaahu ‘alayhi wa sallam, said: "Do not slaughter but a mature (sacrifice); if it is difficult to find it, then you may slaughter a young ewe." [Muslim] The mature sacrifice is from camels, cows or sheep that reached the age stated by Sharee`ah. It was not reported that the Prophet, sallallaahu ‘alayhi wa sallam, sacrificed other types of animals nor commanded his Companions, May Allaah Be Pleased with them, to do so. Consequently, it is obligatory to follow him. 

* The second condition: the sacrificial animal should have reached a certain age; as the Prophet, sallallaahu ‘alayhi wa sallam, said in the above-mentioned Hadeeth: "Do not slaughter but an old (sacrifice); if it is difficult to find it, then you may slaughter a young ewe." [Muslim]

An old camel is the one that has completed five years. An old cow is the one that has completed two years. An old sheep is the one that has completed a year. A young sheep is the one that has completed six months. The best sacrifice is camels, then cows then sheep. A camel or cow is enough for seven persons. A sheep is enough only for one person. It is better for one to sacrifice an animal alone than to share with others in the same animal.

* The third condition: It should be free of certain defects. Al-Baraa’ ibn ‘Aazib, May Allaah Be Pleased with him, in a Marfoo‘ Hadeeth said: "The sacrifice of these four (animals) is not permissible: the one-eyed whose defect is obvious, the sick whose sickness is obvious, the lame whose limping is obvious and the broken (or the fleshless as in another narration) which is too weak to grow a brain." [Abu Daawood, An-Nasaa’i, At-Tirmithi and Ibn Maajah]

There are some disliked defects that should be avoided in the sacrificial animal but they do not render the animal rejected, such as one whose horn, ear or tail is cut and similar cases.

It is better to choose a perfect animal in terms of fatness, abundance of flesh, beautiful look and expensive price. Allaah The Exalted Says (what means): {That [is so]. And whoever honors the symbols of Allaah - indeed, it is from the piety of hearts.} [Quran 22: 32] Commenting on the verse, Ibn ‘Abbaas, May Allaah Be Pleased with them, said: "Honoring means choosing a fat, great and good animal."

* The fourth condition: It should be slaughtered in the prescribed fixed time under Sharee‘ah. It starts after the ‘Eed prayer if one stays in a place where that prayer is performed in congregation. As for a person who can not perform the prayer due to a travel, etc, one should slaughter after a time enough for performing the prayer. If he slaughtered before the prayer, it is just meat that he offers to his family. In the Hadeeth narrated on the authority of Al-Baraa’ ibn ‘Aazib, the Prophet, sallallaahu ‘alayhi wa sallam, said: "The first thing we should do on this day of ours is to pray and then return and slaughter (our sacrifices). So anyone who does so has acted according to our Sunnah (way); and whoever slaughtered before the prayer then it is just meat that he offers to his family and would not be considered as a sacrifice in any way…." [Al-Bukhaari] In another narration, “Whoever slaughters before the prayer has only slaughtered for himself, and whoever slaughters after the prayer has perfected his ritual and fulfilled the Sunnah of Muslims.”

According to the sound view, the time of sacrifice lasts until the sunset of the last day of the days of Tashreeq, the 13^th of Thul-Hijjah. This means that the period of slaughtering is four days. In a Hadeeth, the Prophet, sallallaahu ‘alayhi wa sallam, said: "Slaughtering is to be made in all days of Tashreeq." [Ahmad. Al-Albaani: Hasan] 

https://islamstory.com/en/artical/1813/conditions-udh-hiyah: