Last week, the National Dairy Council (NDC) ran an advertisement (pictured) in this publication with cows in the shape of a question mark on a green field. The question was then spelled out underneath the image – “Why are Centra, SuperValu and Tesco so big on locally sourced and packaged milk with the NDC trademark?”Three of the big players in the Irish supermarket scene, with over 50% market share between them, Dunnes Stores, Aldi and Lidl were missing, so I was asked a number of times over the weekend why they were not listed in the advert by the NDC.