Difficult to get cow manure, horse manure is easy, but that is likely to have lots of wood shavings
Alternatively, just ask for your local farmers stables (poo) . At least, you know where the (poo) is coming from. Make sure it's well rotten for a while. (y)
Not too sure where you got the info that it contacins a lot of wood chipping. Reading the reviews on the Wickes site, can't see anyone complainign it is full of wood chipping. Even if it is just compost, at this price its a great soil conditioner
A useful article from the RHS on using manure in the garden: rhs.org.uk/advice/profile?PID=865 Given these bags contain lots of woodchip mixed in with the manure, I found the following of concern: "Nitrogen lock-up: This can occur where organic matter contains too much carbon rich material in relation to its nitrogen content. Stable manure with wood chip bedding material present or bark chips have a low nitrogen to carbon ratio and should be used with caution, adding extra nitrogen-rich fertiliser" Sounds like you may need to apply some additional fertiliser as well when using this.
sorry to sound stupid but when does this deal run please?