Two of the UK's largest dairy companies - Robert Wiseman Dairies and Dairy Crest - delivered their annual results this week and a comparison between the two makes for some interesting reading. Robert Wiseman reported a near 30% plunge in profits as its liquid milk business was hit by poor trading conditions, while Dairy Crest showed the benefits of being a broad-based dairy firm, delivering a 5% increase in profits. Katy Humphries takes a closer look.