Once the animal is down the slaughterer will recite the following Du'aas:
اِنِّيْ وَجَّهْتُ وَجْهِيَ لِلَّذِيْ فَطَرَالسَّمٰوٰتِ وَالاَرْضَ حَنِيْفًا وَّمَا اَنَا مِنَ الْـمُشْرِكِيْنَ
(Trans.) I have firmly turned myself towards Him Who Has Created the heavens and the earth, and I am not among the Mushrikeen.
اِنَّ صَلاَتِيْ وَنُسُكِيْ وَمَـحْيَايَ وَمَـمـَاتِيْ ِلِلّهِ رَبِّ الْعَالَـمِيْنَ لاَشَرِيْكَ لَه وَبِذَالِكَ اُمِرْتُ وَاَنَا مِنَ الْـمُسْلِمِيْنَ
Verily my Salaah, my sacrifice, my life and death are for Allah, Lord of the worlds. He has no partner; and with this have I been commanded, and I am among the Muslimeen.
اَللّهُمَّ مِنْكَ وَلَكَ
O Allah!(This animal is) from You and (it is being sacrificed) for You.
After reciting above Du'aas softly, say the following words:
بِسْمِ اللهِ اَللهُ اَكْبَرُ
In The Name of Allah.
Allah is The Greatest
Upon uttering these words, slaughter the animal swiftly and with the as few strokes of the knife as possible. The above words must be said right at the time of slaughtering.
In a Hadeeth narrated by Shaddad bin Ows (Radhiyallaahu anhu) Rasoolullah(Sallallaahu alayhi wa Sallam) said:
"Verily Allah has ordained proficiency in everything. So when you kill be proficient.......; let the slaughterer sharpen his knife and give quick relief to his animal." (Targeeb)
After the animal has been slaughtered, say the following Du'aa:
اَللّٰهُمَّ تَقَبَّلْهُ مِنِّى كَمـَا تَقَبَّلْتَ مِنْ حَبِيْبِكَ مُـحَمَّدٍ وَ خَلِيْلِكَ اِبْرَاهِيْمَ عَلَيْهِمـَا الصَّلَاةُ وَ السَّلَامُ
O Allah! Accept it from me like You accepted from Your Beloved One, Muhammad and from Your Friend Ibraheem (Salaat and Salaam upon them both).
If one is slaughtering an animal on behalf of another the niyyat should include the name of that person, e.g. "O Allah, I intend sacrificing this animal for so and so". Then when making the above Du'aa, in place of the word minnee, say the name of that person after the word min- مِنْ