Unless your up against some kind of deadline, I wouldn't worry about the time it takes to get them to your desired weight. If it takes them longer to get to butcher weight, you most likely not encounter some of the problems that can occur from a bird growing too fast. People seem to be convinced that if you don't have a 4 pound bird in 6 weeks, there is something wrong. The six week time frame is based on the time it takes the big producers to put birds on the grocery store shelves. I doubt you have a set-up like a big producer. With only having three birds, you could easily have 3 that are a little slow. I have 63 of them right now that are 7 weeks old, and there is a 2 to 3 pound difference from bird the biggest to the smallest bird.
I think it is a good idea to do a few batches to set your baseline. I have found that it takes my birds 8 weeks to get an average of weight of 4.5 pounds. That is the size bird my family best utilizes. I do each batch exactly the same, and get the same results everytime. I use the same feed, schedule, and housing for every batch.
Don't get discouraged. Establish your baseline, and if it works, keep doing it. If it doesn't work, make changes, and see if the changes get you the desired results. Bottom line is everybody is going to get different results based on how you do things. At the end of the day, you need to find a way that works best for you, and produces birds that suit your family's needs.
I think it is a good idea to do a few batches to set your baseline. I have found that it takes my birds 8 weeks to get an average of weight of 4.5 pounds. That is the size bird my family best utilizes. I do each batch exactly the same, and get the same results everytime. I use the same feed, schedule, and housing for every batch.
Don't get discouraged. Establish your baseline, and if it works, keep doing it. If it doesn't work, make changes, and see if the changes get you the desired results. Bottom line is everybody is going to get different results based on how you do things. At the end of the day, you need to find a way that works best for you, and produces birds that suit your family's needs.