However, so few products are exactly the same that we need to be careful if/when we see adverts promoting “the cheapest bird food in Britain.” In my experience – cheap bird food isn’t that good and the cheapest bird food in Britain isn’t likely to be better, it’s likely to be worse.
Everything has a cost – even the tiniest of seeds has its place on the commodity market, and the market dictates the cost manufacturers have to pay for the seed. Things selling below their market price should set alarm bells ringing.
Take, for example, a high calorie Sunflower Heart - selling this seed for less than it costs in the first place is only achievable if it’s mixed (diluted) with a cheaper seed, a seed that costs less and is less desirable/nutritional. Continuing to dilute the original seed by adding cheaper seeds to the mix will make a mix ultimately cheaper; however, eventually, a point is reached where that original seed becomes almost unidentifiable and the mix has lost its original value.
When it comes to bird food – if it’s cheap, it’s (probably) because it is cheap. Avoid it.
There is a scientific reason to avoid cheap, dusty seed, and that's because it's harmful to a bird's respiratory system and dust can harbour harmful bacteria. How do we know? Please take a look at the work we’re doing at Haith’s PRO to eliminate dust and extraneous husk: http://www.haiths.com/why-we-superclean-our-bird-diets/