The company had commenced construction of the Aylesbury dairy in February 2012, with an investment of £150m.
On reaching full production, it is expected to be the world's largest fresh milk facility featuring advanced and efficient processing equipment with an aim to be zero carbon.
Arla Foods CEO Peter Lauritzen said, "Our Aylesbury dairy is the largest single investment for the cooperative and, as market leader, Arla is setting the future standard for the dairy industry. We are now beginning to ramp-up our operations."
Since 2007, Arla has invested more than £500m in the UK.
In August, Arla Foods amba, Milk Partnership, Arla Foods Milk Partnership's (AFMP) investment company have announced the proposal for the roadmap to co-ownership, in a move to see 1,600 British dairy farmers become co-owners of Arla Foods amba.
On 9 October, Arla Foods approved the proposal for MPL (AFMP) farmers to be co-owners of Arla Foods amba from 1 January 2014.
Earlier this month, Arla said that 85% of AFMP AFMP have already signed up to become co-owners of Arla Foods amba.
AFMP chairman at the time said, "The farmer board is absolutely delighted that so many members have committed to becoming co-owners.
"This says that members and the board have the same vision to share in the success of Europe's largest dairy cooperative and demonstrates democracy in action, with each of the 1,300 AFMP members being given a choice of contracts."
The deadline for all farmers to have signed a new contract to become co-owners is 30 November 2013, prior to full cooperative membership.