The Prophet ﷺ forbade sacrificing an animal with a damaged ear or horn.
أن النبي ﷺ نهى أن يضحى بعضباء الأذن والقرن.
Narrated by Abu Dawud (2805), Tirmidhi (1504), Nasai (4377), Ibn Majah (3145), and Ahmad (633, 1048), through multiple routes from Qatada, from Jurayy bin Kulayb, from Ali, and he related it. The wording given is that of Abu Dawud. The wording found in the others, apart from Ahmad in the first place, is, "He forbade sacrificing an animal whose horn or ear was cut off." All of them except Ibn Majah and Ahmad in the first place added, Qatada said, I mentioned that to Saeed bin Musayab, and he said, "Adb (cutting off) means reaching half or more than that."This statement of Qatada was narrated by Abu Dawud (2806) directly after the hadith, through the route of Yahya Qattan, from Hisham Dastawai, from Qatada. Tirmidhi said, "A hasan sahih hadith." Hakim narrated it (4/224) through this same route and judged its chain sahih.I say, its chain is hasan because of Jurayy bin Kulayb. Abu Dawud said right after the hadith, "Jurayy is a Sadusi from Basra, and no one narrated from him except Qatada. Qatada is a leading authority in this field, and his narrating from him strengthens his standing." Abu Dawud's statement indicates that Jurayy was known in his own town, and had there been any fault in him, Abu Dawud would have pointed it out.As for Ali bin Madini's statement, "He is unknown, I do not know of anyone who narrated from him besides Qatada," he means that his narrations are few. Ajli and Ibn Hibban both judged him trustworthy, and Tirmidhi and Hakim both graded his hadith hasan and sahih.As for what has been narrated from Abu Saeed Khudri, who said, "We bought a ram to sacrifice, and a wolf attacked its buttocks or its ear, so we asked the Prophet, and he instructed us to sacrifice it anyway," this is extremely daif. It was narrated by Ibn Majah (3146) and Imam Ahmad (11274) through the route of Sufyan Thawri, from Jabir bin Yazid (that is, Jufi), from Muhammad bin Qaraza Ansari, from Abu Saeed, and he related it.Its chain is extremely daif, for it contains Jufi, who is discarded as a narrator, and Muhammad bin Qaraza was narrated from solely by Jufi, making him unknown, as stated in Taqrib. Busiri said in Misbah Zujaja (3/54), "This is a daif chain, containing Jabir bin Yazid Jufi, who is daif and has been accused of fabrication."