I have fed Hills for nearly 20 years, and the Natures Best menu is free from preservatives, colourings etc
http://www.hillspet.com/zSkin_2/_refacing/mini site/MinisiteLeftNav.jsp?FOLDER%3C%3Efolder_id =1408474395183160&bmUID=1191597619661&bmLocale =en_GB
or
Burns
http://www.burns-pet-nutrition.co.uk/
or
James Wellbeloved
http://www.wellbeloved.co.uk/
the bigger the bag you buy the cheaper it will be, I always buy the 18kg breeder bag direct from Hills which is around �10 cheaper than the pet store, and delivered to my front door. One bag lasts three dogs six weeks - however, I do give them veggies and fresh meat on top for taste.