I recently came into possession of a quad of Crevecoeurs, and in Canada...the gene pool is particularly shallow. I would love to dedicate my time to helping this breed recover & breed towards its traditional purpose as a table bird. Looking for any suggestions.
With only 4 birds to breed, (as you said) you have a limited gene pool to work with. What characteristics are
not found in the birds that you want to improve?
If I was in your shoes, I would do some crossing between the birds and see if I could improve a characteristic. When you do your crosses, you will have to produce a bunch of chicks (100) at once or a bunch over time.
Keep accurate records of which chicks came from which parent.
For example, if you cross the male bird ( I am assuming you have only one male) with hen A and you produced 100 chicks. From this 100, you have two females that are larger than the parent hen and one male larger than the parent male- you know which hen carried the autosomal or sex-linked gene(s) that when paired with the parent male produced a larger bird.
The next step to do a cross between the larger male offspring and his two sisters. Produce a bunch of birds and analyze the results. Determine if size has improved or not.
If the first cross only produces female offspring that are larger, you know that a sex chromosome carried by the male may be responsible for the larger size and some locus on the chromosome may be responsible for the larger size. (this would be true for subsequent crosses also)
If the first cross only produces larger males, then the female carried a sex chromosome that when combined with one or both of the male sex chromosomes carried the growth factor locus. (this would be true for subsequent crosses also)
If size is a problem, you have to remember- size usually takes a large number of crosses to obtain a goal. Size like
dwarfism is usually associated with a single locus and that can be sex-linked or autosomal. In either case, the dwarfism is pleiotropic ( effects a number of characteristics and systems) and is due to reduced amounts of a growth factor or reduced number of receptors for the growth factor.
You will want to go in the opposite direction. You will want to increase the things that cause the bird to grow faster and larger, This could be something like the bird is hungry most of the time and eats more food or the bird has a thinner lining on the intestine that will allow for the blood stream to absorb more nutrients. It could be that the bird inherits a locus that increases the amount of growth factor produced by a gland or the brain.
Today's table birds grow fast and can obtain large sizes in a very short time. This is accomplished through quantitative loci. In other words, a number of different genes and parts of the DNA in a bird are all working together to produce the rapid and large growth.
Many people think only genes control characteristics but there are also parts of DNA that control the expression of a gene. So when breeding, it may not be a gene at all that is causing an outcome but a part of DNA that is controlling the gene expression (larger size). Sometimes it is a gene regulator that is needed to increase growth and not a gene.
If you want to out cross, that is a possibility if your birds do not have the genetic makeup to grow larger.
If you outcross to a different breed, there are a number of different ways to accomplish the goal.You just have to get started and go from there. I would be glad to work with you on your project. You can PM me and I will give you my email address. I have worked with broiler crosses in the past and have read up and studied the subject.
I am going to be breeding offically Swart Honas, using three out of the four birds I own so I plan on using line breeding to develop my strain until I aquire a good quality rooster to sire a secondary line.
