Hi all! I have seven heavy breed chickens and I used to let them free range in the yard for a good part of the day, but now I am back to work and it is dark when I get home and also my hens have been flying over the fence into my neighbor's yard. Now they are confined to their 5x10 run except for about 1/2 hour in the evening. I got one of those large Purenna Flock Blocks, about 10 inch square. If I put it in the run with them during the day will they choose that over their pellets to the point of not getting what they need nutrionally?