The Messenger of Allah ﷺ said, "A young sheep is acceptable as a sacrifice."
حدثنا عبد الرحمن بن إبراهيم الدمشقي حدثنا أنس بن عياض حدثني محمد بن أبي يحيى مولى الأسلميين عن أمه قالت
أن رسول الله ﷺ قال يجوز الجذع من الضأن أضحية
Its isnad is daif. Ahmad reported it (6:368) from Anas bin Iyad, through the same chain. Umm Muhammad, the mother of Muhammad bin Abu Yahya, is "acceptable," meaning of unknown status, as stated in Taqrib, and the hadith that follows makes it unnecessary.