In Aquiqua and sacrifice...
In Aquiqua and sacrifice, as mentioned above, it is necessary to have the 'niyyet' (intention) that you are slaughtering the animal for that particular purpose Qurbatan llallah (i.e., in obedience to the command of Allah). Other necessary conditions for the slaughter of any animal are as follows:- The person who slaughters must be a Muslim. The knife must be of iron or steel. At the time of slaughtering, the face, hands, feet and stomach of the animal must be towards Quibla.
Also, the person slaughtering that animal must be facing towards Quibla. Before begining the slaughter, when the knife is put on the animal's throat, the person must say 'Bismillah' with intention of slaughtering it. The animal should move its body or limbs after slaughter before dying. Also it is necessary that as much blood should come out of its body as normally comes out from such animals.
Aquiqua: Before slaying the animal for Aquiqua, this Dua is Sunnat : Bismillahi wa billahi Allahumma hadhihi Aqiqatun an (name of the child and his father) Lahmuha bi lahmihi wa damuha bi damihi wa adhmuha bi adhmihi wa sh'aruha bi sh'arihi wa jilduha bi jildihi Alla-hummaj'alha waqa-an li (name of child and his father).
If the child is a daughter, then after taking her name first time, the remaining Du'a will be recited as follows :- Lahmuha bi lahmiha wa damuha bi damiha wa adhmuha bi adhmiha wa sh'aruha bish'ariha wa jilduha bi jildiha Allahummaj-alha waqa-an li (name of child and her father).
Another Du'a : Ya qaume' Inni bari-un mimma tushrikuun Inni wajjahtu wajhiya lilladhi fataras-samaawaati wal ardha hanifam muslimanw wa ma ana minal mushrikiin Inna Swlaati wa nusuki wa mahyaya wa mamaati lillahi Rabbil-Aalamiina La sharika lahu wa bi dhaalika umirtu wa ana minal muslimiin Allahumma minka wa laka Bismillahi wallahu Akbar. After slaughtering, say: Allahumma Swalli ala Muhammadinw wa Aali Muhammad wa Taqabbal min (name of child and his/her father).
Sacrifice at Eid-ul-Hajj time: Before killing the animal, this Dua is Sunnat: Wajjahtu wajhiya lilladhi fatarassamaawaati wal ardha hanifam muslimanw wa ma ana minal mushrikiin Inna swalaati wa nusuki wa mahyaya wa mamaati lillahi Rabbil-Aalamiina La sharika lahu wa bi dhaalika umirtu wa ana minal muslimiin Allahumma minka wa laka Bismillahi wallahu Akbar. After slaughtering, say: Allahumma Taqabbal minni.