Chaz, our male worker, and Milly, our show strain bitch, are both fed on Acana but occasionally Orijen as well to provide a bit of variety in their diets. Both are made by the same Canadian manufacturer and we've found no problems with the dogs swapping from one to another.
Both kibbles are highly rated and, although rather expensive, the smaller amounts required brings the cost down to that of more run of the mill dog foods.
Working cockers are like that though, 6 miles a day over three walks is just a quiet stroll in the park for them but it's very important to keep their brain active by providing mental stimulation as well. If your worker is getting hyper it may be best to provide some sort of game or task, looking for her kibble hidden around the house or in a Kong for instance, to keep her mind occupied.
Our standard walk with Milly and Chaz is just over five miles on the map with the majority being off lead but, while Milly will stick fairly close to us, Chaz can easily double or triple the distance walked by casting about through the heather, trees and undergrowth. Two and a half to three hours later Milly, along with two tired owners, arrive home but Chaz is just getting his second wind
Bob.