Sacrificial Animals

What is the ruling on making supplications at the time of slaughtering animals? The supplication we recite at that time is, “O Allah, send peace and blessings upon our master and prophet, Muhammad (may peace and blessings be upon him and upon his family). O Allah, accept this from us as you accepted the ransom of our master Isma’il by our master Ibrahim (may peace be upon them). O Allah, make this act of ours and all that is with us and from us purely for Your honorable sake and make it a key to all gates of goodness and a seal upon all gates of evil.” Then we say, “May we and they receive the same measure of reward and blessings —those who have rights over us and those upon whom we hold rights, the forgotten, the deprived, all of Allah’s servants, and the souls of our parents and grandparents throughout time from the creation of the world until the Day of Meeting. In the name of Allah, Allah is the Greatest, glory be to Him Who made slaughter [of animals] lawful for you.” What is the ruling of Islamic law on this?

What is the ruling in Islamic law on a banquet that a person holds upon marriage and invites others to?

How should the sacrificial animal be divided? Should each part be divided into thirds—for example, one-third of the liver, one-third of the head, and so on? How exactly should the division into thirds be carried out?

What is the ruling on donating the value of a sacrificial animal to a needy patient? My sister is currently battling cancer and the cost of treating this disease is very high, leaving her without adequate resources necessary for treatment. My son wants to donate the value of our sacrificial animal to her. Is this permissible?

Is it permissible for our company to purchase sacrificial animals on behalf of employees working in the public sector and pensioners who wish to offer the sacrifice? We will be acting as intermediaries, facilitating installment payments between purchasers and specialized breeding and selling companies. The process would involve receiving the cash amount payable to the sellers via banks and paying it in cash to their outlets. The customers would then repay the bank in installments. Would this arrangement have any impact on the validity of the sacrifice?  Is a cow equivalent to seven sheep?