Sayyiduna Imran bin Husayn (may Allah be pleased with him) says: A two-toothed animal is more beloved to me than an old one; Allah Almighty is most deserving of youth and excellence. The two-toothed animal most beloved to me is the one I most love to sacrifice.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19092