It was the practice of the Prophet (peace and blessings be upon him):
"He (peace and blessings be upon him) would slaughter his sacrificial animal with his own hand."
Hadith Referenceصحیح الجامع الصغیر / حرف الكاف / 4942
Hadith Gradingالألبانی:صحيح
Hadith Takhrij[حم] عن أنس. حم ٣/١١٨، ١٤٤، ٢٥٨، ق: أضاحي.