The information in the following is made up of things I have been taught by long time keepers of Persian pigeons, as well as things I have learned from years of my own hands on experience and a few bits of my own personal opinions, please keep in mind that there are as many different ways of doing things as their are pigeon fanciers, the following just happens to be my method.
My Breeding system: First and foremost I pair my birds based on their flying ability and lineage. I am a flyer to the core and I value performance in my birds above all. Now, if I happen to be able to set up a pair that will produce excellent flying offspring who have great colors, patterns and physical build, then its is a win/win situation but that is never my ultimate goal. I breed most of my pairs in individual wire pair cages, this style of breeding offers the fancier confidence that the young from any given pair are 100% pure. More often than not, the babies bred in these individual pens grow faster and turn out better than those produced in an open loft situation. the wire bottoms of the cages allow the droppings to pass through and in turn keep contamination from building up and causing disease. I am not in any way knocking the open loft breeding style, it is much easier and allows more pairs to be bred at once, many times the babies turn out fine and are more than likely pure to that pair, but if one has the means and time, i would recommend individual breeding. My breeders are fed 19% protein pigeon mix with popcorn ( instead of large kernel corn). A protein level of 16.5%-21% is the general recommended range, any lower and the young do not develop to the full potential, and any higher results in, among other things, problems related to the body of the bird growing faster than the skeletal structure can handle.
My flying system: At the age of roughly 3 weeks I start to take my young from the nest as a group and sit them on the loft roof that they will be flying out of I introduce them to the trap and as they start to chase grains they learn to operate the trap. I allow them a few minutes to a half and hour per day of supervised time there before returning them to their parents ( NOTE: it is important to keep a close eye on your babies at this time, they are vulnerable to a wide range of predators even some that may not normally feed on adult pigeons, such as crows and other corvids). when the young are eating and drinking well on their own I separate them into their own loft with only young birds and one or two females that will in a sense be their mentors, here is where my system differs from some, I do not train to droppers as I have never had great success when using droppers with IHF, other breeds like tipplers respond well to droppers but many Iranians are "in the zone" when they are flying and will ignore other pigeons completely. My babies learn to come back into the loft by whistle, this works while they are young and still in the early flying stages, after that it works well to call them in from the roof once they land on their own, however, through repetition they usually end up landing then trapping directly into the loft without being called.
Here is where the Iranian differs from many breeds, not every family responds to the same methods as the next family, and even within that family, some birds may act different than even their siblings, this is more so the case when dealing with a newly established line of birds than when dealing with a long standing proven family. Some lines will start performing on or slightly before the second week of flying others take months, sometimes up to a year to show their true potential. I start letting my babies out on a daily basis in small groups so as not to risk losing all of them should something happen ( raptor attack, odd weather change, loud noises etc). after a week or so of this i study them to see which birds share similar behavior ( many times i know what to expect as i know the general behavior of that family of birds), I then group these birds together and start flying them in kits. The birds that seem to be maturing faster and starting to come into their own will be separated and flown with each other, the other birds who seem to be taking their time are flown with the older hens who know the ropes and eventually start dragging those birds up with them. As these slow starting birds begin to perform they are placed with the group that is more advanced. The rest is just repetition. I find it best to fly them every day until they start to fly more than 4 hours, after that they are flown 3-4 times a week since these extended times take more out of the bird.
IHF do not respond well to the same conditioning as a tippler or other flying breed, one should avoid the practice of trying to "cut weight" as is common in these other breeds. IHF need to build endurance and muscle by flying regularly on a good diet with good levels of carbohydrates and protein. I feed a 15.5% protein mix without popcorn, I add to this safflower, as awell as red and white proso millet the ratio is basically this = 1/4 pigeon mix,1/4 safflower, 1/4 red proso and 1/4 white proso. All of which contain good usable carbohydrates. Think of these birds as a top level race horse, grass hay or cheap feed will not lead to top performance, in turn IHF do not fly well on a diet of just cheapo wild bird feed or low protein bottom line pigeon feeds (these feeds can however be used as a maintenance feed for birds who are not flying, breeding or moulting, if needed).
My ideal IHF: My goal when breeding is to produce a bird that flys high for hours on end and tumbles well. I like my birds to fly with their tails fanned and using thier wing tips in a slow butterfly like fashion, birds that can fly this way are almost sure to put in many hours. I like birds that want to fly, I prefer to open the door and have the birds take off, I try not to toss my birds up. The best birds to me are the ones who leave the loft and head up at a 45 degree angle, not circling, just tumbling and heading straight up. Birds that fly like this are just about every IHF keepers dream. There needs to be a balance in tumbling and time flying, birds who tumble constantly will burn themselves out in a much shorter time than those who tumble less frequently, this is part of the art of breeding IHF. I prefer birds with broad, strong feathers who when relaxed, hold their plumage in a semi loose fashion , I do not mean rough feathering, but not as tight as racing homers hold their plumage. To give an example, if I were picking one bird from a loft of 100 and knew nothing of its flying ability I would choose the bird with long tail feathers at least the width of both of my thumbs next to each other, long Primary and secondary flight feathers that are pliable, soft and not less than 1/2 the width of the tail feathers. a well muscled body with a big powerfull chest and deep keel, both traits belying a good set of lungs.