I have 5 meat birds that have, over the past 7-10 days, developed a golf ball sized hard lump on the right side of their necks around their breatbone. Other than not being as big as I had expected them at 4 weeks, they seem to be otherwise healthy. No apparent problems breathing, eating or moving. I've been through the chicken health handbook, but without an idea as to where to start, I just don't know what to look for to figure out what is going on with the meaties and whether or not they will be able to serve the purpose for which I had intended them. Any insight would be greatly appreciated. Thank you.