My girls are 18 weeks old. I have maybe 5 pounds of start n grow left. I buy the feed 100 pounds at a time since I have to drive 30 minutes to get to the feed store. Should I get more start n grow or go ahead and get layer? I don't want to be stuck with 100 pounds of start n grow if my girls start laying in the next week or so. Also, my 1 year old roo is eating whatever the girls eat. I have 50 pounds of "rooster buster" for him but he wants to eat the girls feed and they want to eat his. Should I just mix the 2 feeds?