Most of the scholars are of the view that it is not obligatory to do wudoo’ after drinking camel’s milk. This is the well-known view of Imam Ahmad (may Allaah have mercy on him). This is indicated by a number of things: 

1 – The basic principle is that things do not break wudoo, and there is no saheeh evidence to suggest that wudoo’ is invalidated by drinking camel’s milk. 

The Prophet (peace and blessings of Allaah be upon him) told some people who came to Madeenah and got sick to drink camel’s urine and milk. Narrated by al-Bukhaari (233) and Muslim (1671). If drinking their milk invalidated wudoo’, the Prophet (peace and blessings of Allaah be upon him) would have told them about that. 

See al-Mughni, 1/245; al-Insaaf, 2/58; al-Sharh al-Mumti’, 1/209 

With regard to the hadeeth narrated by Ahmad (18617) and Ibn Maajah (496) from Usayd ibn Hudayr (may Allaah be pleased with him) who said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Do not do wudoo after (drinking) sheep’s milk but do wudoo’ after (drinking) camel’s milk,” and the hadeeth narrated by Ibn Maajah (497) from ‘Abd-Allaah ibn ‘Umar (may Allaah be pleased with him) who said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: “Do wudoo’ after (eating) camel meat and so not do wudoo’ after eating mutton; do wudoo’ after (drinking) camel’s milk but do not do wudoo after (drinking) sheep’s milk,” both of these ahaadeeth are weak and cannot be quoted as evidence. They were classed as da’eef by al-Albaani in Da’eef Ibn Maajah. 

Even if this hadeeth were saheeh, the command mentioned therein could be understood as meaning that it is mustahabb to do wudoo’ after drinking camel’s milk, so as to reconcile it with the hadeeth quoted above.