Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said, and then he narrated the hadith, and in it there is also: "There is no owner of camels who does not give their due, and part of their due is milking them on the day they come to water, except that they will be gathered for him on the Day of Resurrection, not a single young camel among them missing. Then he will be laid down for them on a level plain, and they will trample him with their hooves and bite him with their mouths. Whenever the last of them passes over him, the first of them will return to him, on a day whose length is fifty thousand years, until judgement is passed between the people, and he sees his path, either to Paradise or to the Fire." Then he mentioned the rest of the hadith.
Suhayl bin Abi Salih narrated it from his father and said in it: "There is no owner of camels who does not pay their zakah," but he did not mention the wording about milking (halb). And Abu Umar al-Ghudani narrated it from Sayyiduna Abu Hurayrah (may Allah be pleased with him) with the same meaning, "whoever does not give their due." It was said: "O Abu Hurayrah, what is the due of camels?" He said: "To give the choicest one, to lend the abundant milker, to lend its back for riding, to lend the stud, and to give milk to drink."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7787