Abdullah bin Mughaffal (may Allah be pleased with him) said: On the day of Khaybar I got a bag of fat, and I kept it aside. I said: I will not give anyone anything from it. I turned around and saw that the Prophet (peace and blessings be upon him) was smiling.
Note: If the fat from the slaughtered animal of the People of the Book is permissible, then the slaughtered animal is also permissible.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19707