Case C-34/08: Judgment of the Court (First Chamber) of 14 May 2009 (reference for a preliminary ruling from the Tribunale ordinario di Padova (Italy)) — Azienda Agricola Disarò Antonio and Others v Cooperativa Milka 2000 Soc. coop. arl (Agriculture — Common organisation of the markets — Milk quotas — Levy — Validity of Regulation (EC) No 1788/2003 — Objectives of the common agricultural policy — Principles of non-discrimination and proportionality — Determination of the national reference quantity — Criteria — Relevance of the criterion of a Member State’s milk production deficit)