We have been feeding Purina Layena pellets, but I have been considering switching to a feed with animal protein. I have heard that Nutrena is such a feed and it just happens to be on sale at Coastal. I think you pay about $11 per 40 pound bag for the first three, and the fourth is 47 cents, if I remember right. Is it really a better feed, and if I switch out, is it better to mix feeds and slowly get rid of the one, rather than just changing completely, all at once?