It was narrated that Usaid bin Hudair said:
"The Messenger of Allah said: 'Do not perform ablution after (drinking) sheep's milk, but perform ablution after (drinking) camel's milk.'" (JA)
English reference (JA): Vol. 1, Book 1, Hadith 496 (JA)
Arabic reference (JA): Book 1, Hadith 535 (JA)