Donrae’s right. At that age it’s really hard to tell how the rooster will behave when he is mature and in charge of the flock. Their behavior can change as the hormones settle down. Also being flock master is a lot of responsibility. Some can handle that better than others.
First, eliminate any that have a physical deformity or you just don’t like the way they look. That could be anything from crooked toes, warped beak, to just a body shape you don’t like. They will pass on that stuff to their offspring.
I don’t know your goals, but if they include meat, you might want to go for a larger early maturing rooster. If you are after eggs only, no meat, size isn’t as important but I think early maturing is still a benefit. Don’t get too hung up on biggest if you are after meat, but size should be a criteria. When I butcher later maturing cockerels I find their sexual organs are usually not very well developed. These are at the bottom of the rooster pecking order too. I just don’t find late maturing cockerels good candidates for flock master.
I look for a cockerel that is near the top of the cockerel pecking order. That kind of goes with the above. A good flock master has to be dominant in his flock to be able to handle his duties. He needs the self-confidence to be able to handle those duties without being a pure bully and brute to the hens. You don’t have to choose the most dominant cockerel but I would pick one near the top.
Are your males running with the females? If they are, you are going to have a pretty hectic time when they hit puberty. If you have lots of room you’ll probably be OK but it can get kind of wild. The boys will be fighting some to determine who is dominant. If you have enough room, that usually involves some running way and chasing after a skirmish. They work it out. Kind of look at who wins these skirmishes. Those are you best candidates.
Some will be trying to mate with the pullets. Some of that is sexual but the mating ritual is also dominance behavior. They are trying to establish flock dominance over the pullets. Again, these are your better candidates. The pullets will probably not be mature enough to know what to do so they will probably not cooperate. The cockerels will probably try to force them. It’s a rough time with all those hormones running wild. If you see a cockerel dance for a pullet before trying to mount her, that is a plus. If you see a pullet willingly squat for a cockerel, that is another good sign, a really good sign.
I don’t know how important color or pattern are to you in the offspring. If you choose a Barred Rock rooster, the first generation will pretty much all be black barred. There will probably be some leakage from the GLW but basically black barred. If you keep some of the offspring for breeding to each other you will get a lot of variation in later generations if you choose a rooster and some pullets from the GLW hens (you can tell by the comb). You can get a real wide variation of colors and patterns, many of which will surprise you if you keep some GLW in the mix, but black barred will probably predominate if you keep a rooster or many pullets from the Barred Rock hens.
If you choose a Buff rooster, the first generation will include black pullets, black barred cockerels, and some buff/light red chicks from the GLW. I’m not sure what the patterns will be but the GLW chicks will be buff/light red. Those black pullets and black barred roosters will possibly have some orange-ish or buff spots or areas. Buff can do funny things when crossed with black or black barred. If you choose breeding stock from this offspring, you can get a rainbow of colors and patterns in future generations.
