I have been using a method for this new breeding season to breed several hens to one cock. It's not that hard to follow. I found it a while ago, going through different pigeon websites looking for info.
The number of young obtainable from one 'stud sire' in one round depends on how many hens you plan on mating to that one cock. It can be 2 it can be 6, 10, 12, 16, etc. it just depends on how much time you're willing to spare for the process. I was able to successfully wean 9 young from from one cock in one round, on my first attempt. I mated 6 hens to one cock I should of gotten 12 but not all the eggs were fertil, 9 is a pretty good number though. All you need is two sections in the loft or two lofts to separate the males from the females. This process is easier when the cock is not mated, and it helps if the hens have all laid and reared young before. You will also need any kind of nest boxes where the hen can be isolated from the cock (widowhood nestboxes, work well)
Now here is where it might get confusing, on paper record the hens being used and also the mate (Original) or new mate as these are the cocks that are going to rear the young as their own, nest box #s, etc.. If you're only mating two hens to one cock this is not needed as the 'stud' cock will help both hens with the young but can be very stressing for him. So when selecting which cock goes to which hen make sure you are thinking ahead, as the 2nd round young will also be be half brother/sister to the first round young of each hen (different father). Unless you plan on doing the bull system for all rounds, then all young will be related.
The loft should be fitted with an aviary or section where the cocks can be locked out or separted when the time comes. I lock them out in the aviary but can also be transfered to another loft (more work). I place a drinker and pots of grit and minerals in the aviary. When pairings are figured out, introduce the cocks into the loft and let them pick out their own nest boxes or old how ever they choose just allow eanough time for them to settle in. Practice the locking out/separating a coulple of times to get them used to the idea.
When ready...
Day 1
Make sure hens are well fed and watered. Better if hens are introduced later in the day rather than earlier in the day. Feed and lock the cocks out in the aviary then place the hens in the locked half of the nest boxes according to which cock they are being mated to, to rear young. It's a good sign that things will go easy when the hens are very amourous and let you know they are ready to pair without a cock present. With the hens locked in their boxes allow the cocks into the loft. They fly up into their box perform their usual stuff trying to court the hen, but cock should not be able to thread hen. Leave birds like this until morning.
Day 2
First thing make sure all hens are still locked and have not scaped the box. If they have it's not a problem at this stage but prevent that from happening again. Feed cocks and lock them out with their own drinker. Once locked out allow hens out to eat and drink. As each hen returns to the nest box (hopefully her own) lock her in. When all locked in allow the cocks in. At this point cocks should rush to their boxes spinning and cooing. Reapeat this once more during the day for the hens to stretch and eat&drink, you can also put little drinkers in the nest box if you wish.
Day 3 and Day 4
For these 2 days do the same as the Day 2.
Day 5
The day to introduce 'Stud' cock. The cock I used was a 9 yr. old. It can be paired alrady or sitting on eggs but you will get quicker results if he's un-paired.
Feed cocks and lock them out. Release hens to eat&drink etc. Lock all hens in their boxes. Bring stud and release him in loft he will strut his stuff and all hens will respond from nest boxes. Allow cock to roam around he will fly upto many of the hens introducing himself. All hens will respond to his attentions. After 10-15 minutes after the stud was introduced allow the hen from the first box out. In no time she will fly to the cock, as soon as the deed is done place the hen back in the nest box and lock her in and remove the cock into his own section let him rest for 30 minutes. Mark down on record sheet alongside the hens ring number that this occured and anything neccessary like date or what you think is important to you. After 30 mins. let the 2nd hen out and let the cock in the loft. This should now go faster chances are that all hens saw the first procedure and will be competing with each other. Rmove cock and lock up the hens. Do this for every hen every 30 minutes. I was able to mate all 6 hens in one day to the stud. Then give the cock a longer time to rest a couple of hours if you have more than 6 hens. Don't forget to mark down each hen in turn. If one refuses to mate make note as she will be the first one with the stud the next day. When all done lock all hens in their nest boxes and let the cocks in. The cocks are clueless as to what's going on.
Day 6
If all went well previous day, do the same but this time in reverse, the last hen to mate with the cock the privious day should be first now. If there were any rebels that did not want to mate they should be the first ones. Don't forget hens have to be well fed before you start.
Day 7
Exactly same as Day 6.
Day 8
Depending on the hens you could be getting eggs at this time. If not continue this (days necessary) until you start to see eggs. If so I suggest that you concetrate on the ones that have not. As I have noticed that once the hens have laid, they will have nothing more to do with the stud. According to where I got my info once the hen has laid 1st egg she will not let the cock thread her again, and that the theory of 2nd egg fertilization needed more looking at.
At this stage allow all cocks back in (no contact) just so that they can see that their hens have laid. As soon as a hen lays her 2nd egg, open the box and allow the cock to enter. Many of them rush in and instantly sit on the eggs, no matter what time of day it is. Once all hens have laid you can start to treat the loft with your everyday loft management. The cocks will have no problem believing the eggs are their own and will sit on them normally. Not all the eggs are fertil sometimes they are.
I ended up with 9 youngsters that ressemble one another in many ways. After the 1st round my original pairs i had planed mated for the 2nd round in normal fashion.