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By: Alan Wheeldon Email: alan.wheeldon@btinternet.com |
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Continued from prior page Remember the genes for each characteristic will be in pairs in the parents but the cock will only pass one half of each pair to the offspring in his sperm and the hen will also only pass one gene from each pair to the offspring in the egg. So lets cross these typical examples and see what type of young they are capable of producing.
Cock........................Hen A range of individuals can be produced from this pairing and youngsters will vary in makeup from a superpigeon right down to a very poor specimen.
LL HH MM RR AA.........CHAMPION PIGEON SUPER ATHLETE So just by using these five characteristics as an example we can surmise that there can be over one thousand combinations. When you consider that most fanciers breed only two young from each pair you can see that they have a long way to go to find that super champion. Luckily things aren't that impossible. Even though a large number of unique individuals can be produced, in our example, a quarter of those hatched will have a large number of the dominant supergenes, half of the young will have an average number of supergenes and the last quarter will have few or no supergenes. So in real terms at least one in four birds bred from this pairing will be a good pigeon. It can be estimated that probably one in twenty will be an excellent pigeon and perhaps one in a hundred will be an exceptional pigeon, a champion. This pigeon will contain most if not all the dominant winning genes from both parents. Of course we have no control over which of the pair of genes are in the sperm that will fertilise the egg or indeed what genes will be present within the unfertilised egg carried by the hen. Remember only half the genetic material comes from the cock and half from the hen. We could be lucky and the first youngbird hatched will contain all of the supergenes from each of the parents. But generally the rule is, the more youngbirds that you breed from a pair, the more chance you have of producing a youngster with that winning combination of supergenes. But remember the winning genes must be present in the parents in the first place, and you can shorten your odds by starting with champions. One method that is used to increase the chance of producing a youngbird with the winning genes is using the Bull or Stallion breeding system. Here a cock can be mated to four, or as many as eight hens within a very short period of time to produce as many as thirty-two youngbirds from a single cock in one season. This dramatically increases your chances of producing youngbirds with winning combinations of genes. Such methods are also used to inbreed and concentrate those very genes. Another less intensive method of increasing offspring from a single pairing is by undersitting eggs from proven breeders of good pigeons to keep the quality of the race team high. But in reality most fanciers will only breed one or two pair of youngbirds from a single mating. From our example you can see that most of the pigeons bred from the pairing will fall in between the two extremes and be slightly better, or just as good as, or slightly worse than the parents. Occasionally just by chance someone will win the lottery and the right combination of super genes will occur in the sperm and egg and combine to produce a super pigeon, but as you can imagine this is rare. An example of such a pigeon would have been 'Supercrack' bred by Mons Hovaert of France, raced by Mons Gruson and finally owned by Robert Venus, an exceptional pigeon, winning at least three national races. That combination of winning genes was passed down to his immediate children and they too were good pigeons, two sons won first nationals, and six of the grandchildren won first nationals, but none were as good as the original Supercrack. You can see that this was, because the winning combination of genes, was diluted, by lesser genes, inherited from the hens, that he was paired to. The champion cock could only pass half of his genetic material carried in his sperm to his offspring and not all of those genes would be dominant. The hens that he was paired to would contribute the other half within the egg. Of course the genes would be diluted even further in the grandchildren when the sons and daughters were paired. This is why you often hear top fanciers use expressions such as 'the apple never falls far from the tree'. Meaning that if you want winning pigeons with the winning genes you need to stay close to the original parentage. The sons and daughters might have some or most of the winning genes but the further away you go from the champion the less likely it will be that the original gene combinations will be intact. They would have been diluted and disrupted. Sons and daughters will only have half the genetic material from the parents, the grandchildren only a quarter. Inbreeding To overcome this problem of winning genes being halved and diluted in the offspring many fanciers use the strategy of inbreeding. By re-crossing a champion cock pigeon for example with its dam, or with it's daughters, or by mating it with its sisters, the winning combination of genes can be concentrated and held together. We can illustrate this by using our original example. To inbreed we should pair the superpigeon, a cock, back to it's dam.
Cock...........................Hen 75% of the young from this pairing will have capital letters – the supergenes. And of course you can inbreed further with one of the daughters from the superpigeon x dam mating, and backcross again to the original superpigeon. By constantly doing this you can concentrate the number of supergenes in the offspring dramatically. In theory you can, with this example, reproduce youngbirds with 100% of the original supergenes. The genetic equal to the original champion. In practice it will take a lot of backcrossing to achieve this. You must remember that there aren't only the five pairs of genes that we are using. In reality there will be tens of thousands. It is thought that to produce a true inbred, a pure group of individuals that have 99% of their genes the same, it would take parent-sibling matings for over 23 generations. But luckily this degree of inbreeding is not necessary to reproduce the winning pigeon, as a large number of genes are responsible for characteristics in the children that are irrelevant to winning races, for example the colour of the feathers. That is why champion pigeons can produce other champions that are not always exactly identical to the parents. It is only the characteristics that make the pigeon race home faster that are important and need to be passed on. Hybrid Vigour So imagine you have achieved a highly inbred family of winning pigeons, how can you make it better? One example of such a family must be the Janssen family of pigeons. This family was developed over generations, inbreeding, racing, selecting the best offspring, and further inbreeding. With an inbred family, to produce even better youngbirds, you need to introduce a new supergene that your own family of inbred pigeons does not possess, you need to add something extra. This is the blessing of an outcross, it will introduce new genes into an inbred family of pigeons. It has been suggested that the introduction of the Fabry pigeon into the Jannssen strain did just that. It introduced fresh genetic material that added something extra to an already good family.
Lets look at our superpigeon example It's got powerful lungs, a strong heart, super efficient metabolism, resistance to disease and a strong homing ability. But it's wings for example may only be average, if it had extra long primary flight feathers it could sweep more air and travel further for every wingbeat.
Superpigeon..........................Outcross By introducing this outcross some of the offspring will inherit combinations of these supergenes from both parents and by inbreeding once again, these winning genes can be concentrated. The result will be a pigeon that now has all the best genes from the old family plus the new genes that produce a better wing structure.
Exceptional champion This introduction will produce a pigeon that is superior to either of the parents. This is known as heterosis or hybrid vigour. And it generally occurs when new supergenes are incorporated within the genes of a highly inbred group of individuals. Regarding the Janssen pigeons I think history shows us that these pigeons are one of the most successful families in which new genes can be introduced using a cross, the offspring often demonstrating hybrid vigour, to produce some outstanding pigeons. An ideal situation in which to produce hybrid vigour is if you have two families of highly inbred pigeons, with each family containing winning genes that produce very different winning characteristics. For example, if you cross a cock from a family that win because they have a highly efficient cardiovascular system, with hen that wins because it has superbly developed wing muscles, the youngbirds from this crossing, will inherit genes that produce both qualities within a single pigeon. This pigeon would be a tremendous athlete, performing better than either of it's original parents. However, hybrid vigour can be a very fragile phenomenon. When it occurs within a loft, unless a careful breeding strategy is carried out, it can soon be lost. I think this frequently happens, and explains why fliers can have a fabulous one, or two seasons, winning prestigious races such as Combines, and then sink into oblivion never to be heard of again. The most simple solution to maintaining hybrid vigour is to keep together the pairs of pigeons that produce the winners and not to introduce any outcrosses. To increase the number of pairs that produce the magic hybrid vigour it is essential to set up two lines of breeding. The producer hen must be line bred back to her father or brothers but never to her sons and the cock must also be line bred back to it's mother or sisters but never to his daughters. The resulting offspring from the two separate lines can then be mated and hybrid vigour will reappear. Best to Best An alternative strategy to produce winners is simply keep pairing best to best, buy in new champion blood, cross this with your best pigeons and keep pairing winners to winners. In this case a variety of winning genes will combine, and they will keep recurring in subsequent generations. An example of such a strategy must be with the Busschaerts. George Busschaert was a millionaire, he bought the best there was in Belgium in the sixties and seventies and brought them to England. The birds were totally unrelated but they had one thing in common they contained a variety of genes that were capable of producing super athletic characteristics in pigeons. They were certainly not an inbred family, but by line breeding the different combinations of winning genes kept reappearing in subsequent generations. This addition of new winning genetic material was further enhanced when fanciers started to cross the Busschaerts with their own winners. This constant introduction of new winning genes from pigeons from different sources explains why the Busschaerts are such a diverse family of pigeon, having every combination of colour, size, shape and form ever seen within a family of pigeons. And it raises the question, what exactly is a family of pigeons. Well George Busschaert had his own definition, and in spite of his pigeons originating from a variety of sources, he said that when they were in his loft they were Busschaerts. This concept of bringing in champion blood, outcrossing and vigorously testing the offspring is used to great success on the continent, particularly in Belgium. If you look at the foundation birds of many of the continental sprint pigeons they come from many diverse sources. Typically the Janssens usually appear in most at some stage. One of the problems associated with constantly outcrossing is that you generally have to breed a large team of youngbirds. This has to be done to increase the chances of producing an individual pigeon with the right combination of winning genes. However once a champion has been found it is then a matter of outcrossing with new winning genes from other champion pigeons; this produces a problem in it's own right. If an outcross does not improve the winning line, then the decision has to be made to remove all traces, in case these new genes dilute or disrupt the winning combination of genes. It is easier to remove birds that have inherited bad gene combinations. In fact they will usually select themselves out when it comes to the basket. A pigeon with poor homing ability, weak constitution or poor resistance to disease will soon become apparent. Breeding Selection If you breed from your race team and you find a race pair that breed winners you should put them to stock immediately. It is a rare occurrence to find such a goldmine pair. You will find out when you race and lose them to a hawk or a wire. You will never find another mating like it again. If you have any doubts just consider the mathematics, you could race the parents and win but you could also comfortably produce 4 youngsters per year for say 10 years and potentially have 40 winners. One further point when breeding, keep comprehensive, thorough records of what is paired to what, make a note of the ring numbers of the youngbirds from each nest. It would be so frustrating if a nest pair of champions was discovered but you couldn't remember who produced them. An ideal breeding set up is one in which pairs of birds are housed in separate sections. In most lofts this is impractical usually because of limitations with space. But it raises an important issue, and that is that pigeons are promiscuous. They will mate with others in the loft if they get an opportunity. If you have a reasonably inbred colony this is less of a problem as the gene pool is relatively homogeneous, however if you do see examples of hanky panky make a written note. Again it would be extremely frustrating if you bred a champion and you hadn't realised that it was from a different cock. If you do decide to introduce fresh blood to improve your race team several points will help to improve your chances of success. Look for a flier that has had consistent success over a number of years rather than the odd good result. If you go to a loft that has a reasonably inbred family of pigeons this will cut down on the number of aberrant genes that you have to select out when testing the offspring. It will also allow the option to practice the introduction of hybrid vigour at a later date. Also look for a flier with a management system that will suit you. For example if a fancier has success with his family of pigeons, but only if he trains them to 40 miles twice a day, you might want to reconsider. It is also important to buy from a family that has had success at the type of racing that you want to do. For example it is no good buying from a fancier that only wins up to 120miles if you want to fly long distances, over the channel. And finally remember that the 'apple never falls far from the tree'. Buy the parents of the champions, the champions themselves, full brothers and sisters of the champions or children of the champions especially if they were the result of a backcross with a grandparent. A dilemma occurs if a pigeon is bought in with a superb pedigree, it might even be a champion itself and yet it fails to produce any winners. Well there are several options. 1) Change the pairing. It could be that it needs to be mated to a different partner for the winning genes to be expressed in the offspring. 2) Persevere. It could be that not enough young have been produced for that elusive winner to show itself. This is a particular problem encountered by those who only fly widowhood cocks. A disproportionate number of hens might behatched and only the cocks will be appropriately tested. 3) Sell the pigeon and try a new introduction. 4) Buy in another similarly bred to the first introduction and start a new line, based on the new champions. In all cases offspring from any pairing must be thoroughly tested using the basket, because winning is the criterion for selection. This also presents a problem, and that is, how long do you keep a pigeon before you can make the judgement that it is no good. Some pigeons perform to their maximum potential as youngbirds or as yearlings, but there are always examples that occur, in which the pigeon has needed to mature to at least 3 years before showing it's true form. I think the choice of when to say that the pigeon has been given a fair chance usually depends on how many pigeons you want to keep. The Effects of Age One other serious consideration when selecting stock for breeding is it's age. If we go back to the mechanism by which sperm and egg cells are made. They are made when a stem cell divides and allocates half of each pair of genes to each sperm, similar events occur when an egg is produced. You can imagine that as a cell gets older this process becomes less efficient and mistakes will be made. It happens in all cells as they age. They find it harder to reproduce exact copies. We see the result of this as we grow old. Our skin becomes wrinkled our muscles weaker. Well the same thing happens when sperm and eggs are produced in older pigeons. Genetic material on the chromosomes gets switched, it becomes muddled and in extreme cases it may breakdown or be altered. The result is that a youngster conceived with this genetic material will look and perform even less like the parent. An extreme example of this in humans, is the increased risk that mothers over 40 have, of giving birth to a Down's syndrome baby. This is why experienced breeders have noted that you stand a much greater chance of reproducing the winning genes if you breed from yearlings than from very old birds. The Future Science has made great advances within the field of molecular genetics. It is now possible to reproduce an exact copy of an individual. This has been achieved with mice, pigs and sheep, and legislation is now being put in place to prevent scientists trying such an experiment using humans. There is no reason why cloning could not be achieved using pigeons. Imagine just by taking the genetic material from inside the cell of a champion pigeon and placing it inside an egg in which all the genetic material has been removed, an identical twin of the champion will be produced. I am surprised that the large studs have not yet started their own cloning program. Technically it would be easier to clone a pigeon than cloning mammals, as the fertilised egg does not have to be implanted into a surrogate female. It just has to be hatched normally in the nestbowl. Imagine being able to buy an identical twin of Magic Blue or Champion Studtopper. And why stop there. Genetic engineering now has the capability of introducing genes from one species and inserting them into the chromosomes of another. This is what is causing so much controversy within the major supermarkets, most of who now ban genetically modified foods. But it's not only crops into which foreign genes have been inserted. It has already been achieved with animals. Imagine taking the genes that allow the swift to fly at up to 150mph and inserting them into the egg of a racing pigeon. Races would be won with velocities of 4400 ypm! A pigeon would fly 500 miles in less than three and a half hours. But these are things for the future. As for now we will have to rely on the tried and tested methods that have proved fruitful over the years. And if you haven't already done so, I hope you all get the chance to breed a champion of your own one day. |
