I am designing an experiment which will have eight free-ranging flocks. Each flock will have a livestock guarding dog with both dog and birds confined by electrified poulty netting. Previously I was considering use of Great Prynees or similar large breed but feed cost appears to be too high so now considering use of a smaller breed such as English Collie. Anyone kept records of annual dog feed bills? Or have experienced based reccomendations on cost effective feeds?