What is Selective Breeding?
Selective breeding is, simply put, breeding with the intent of accomplishing some type of goal. Usually, the goal is multi-faceted. It takes into account various traits, the overall health and vigor of the chicken, the reasons you have for raising the chickens and the way (and place) in which you are raising them.
Any breeding with the intent of improving the breed is selective. This is true not just of chickens, but also cows, horses and other animals. Breeding that’s not selective tends toward mediocrity. Just like anything that care is not being put into, the breed will tend to degenerate over time and become average or worse.
In selective breeding, we keep (i.e., we select) only some of the offspring from our matings as future breeders. To determine which ones to keep goes back to our goals and where we are in our breeding program. From our goals, we have a set of standards. Chickens that best meet those standards will become future breeders and those that don’t won’t.
The more selective we can be in which chickens we keep as breeders, the faster we can improve our chickens.
How do we know which chickens to keep as breeder and which ones to cull?
That goes back to the goals of your selective breeding program. Based on those goals, you will come up with a written set of standards for your chickens. The standards will help you know what to cull for. It will clarify which chickens are most ideal and desirable for use as breeders.
If you’re raising heritage breed chickens, such as the Australorps that I’m raising, you will begin with a breed standard, such as the one published in American Standard of Perfection. This book tells the desired traits for many different breeds of chickens. It declares what traits are considered defects, it specifies a proper weight range for chickens, along with plumage color, plumage pattern (if applicable), body shape, eye color, comb size and shape and many other traits. The purpose of the Standard is to define what is a good representative of each breed. Without a standard, any type of breeding will tend to deviate, and the chickens will gradually become less and less characteristic of the breed they initially came from.
The Standard is an excellent starting point, but you will likely have additional goals in mind. You may aim to have hens with a certain degree of broodiness. Or you might focus more on disposition, desiring chickens that are calm, friendly or easy to tame. You might aim for the upper end of the Standard’s weight range. Or the lower end. Or you might aim for consistently high egg production. Your goals as a breeder taken together with the breed standard will define what you consider to be an ideal bird versus a mediocre bird. I recommend that you write down your standard. This will allow you to more easily review it and improve and clarify it over time. Your standard will guide you with selecting and culling your chickens.
Culling and Selection
What do I mean by selecting and culling?
I view these as two different steps. First I cull the worst chickens. We use those for meat. Later, I select the chickens as breeders. “Worst” and “best” relate directly to the standard discussed above.
Let’s go over this in more detail.
When to Cull
Before culling, I recommend raising birds to maturity unless there is some defect that would cause the bird to be in pain or picked on by other chickens or something along those lines. Raising them to maturity accomplishes two things. For one, you get a better idea of how the chicken will turn out. And second, he or she will be large enough to process for food. Breeding chickens goes hand-in-hand with raising them for food (both meat and eggs) and it would be wasteful to cull a chicken early that could otherwise be grown up to become food for the table.
Males will mature at around 16 to 22 weeks. Females, around 26 weeks, when they start to lay. Your chickens will not be fully grown at that time, but they will be developed enough that you can recognize any obvious defects. Cull any birds that have defects such as a slipped wing, a split wing or toe problems and any other clear defects set out by your breed standard.
When to Select
Once you’ve culled the worst representatives from your flock, you will be (hopefully) left with quite a few chickens. These will include birds ranging from mediocre to very good, possibly excellent. At this point, I recommend continuing to raise the chickens until it becomes very apparent which birds are your best, your standouts. It’s better to only use birds that are a year old or older in your breeding program anyway. Growing the birds out longer gives them time to fully develop, to demonstrate their laying and fertility, and to prove their disease resistance. It also gives them time to go through a molt, toward the end of their first year.
As these birds are developing, you will notice some that are of poorer quality, based on your breeding standards. Culling these when you begin to recognize those problems, but be careful not to cull too many. You need to be sure to keep enough birds for your breeding program plus some spares. You want to be selective, but not so selective that you keep too few chickens as potential breeders.
Be aware that some birds that do not seem excellent to you at 6-8 months of age may become your favorites later. You may discover that they have exceptionally good disposition (an especially desirable trait for a rooster). Or you may discover that a particular pullet broods well and raises her young better than any others. Those may make them desirable for your breeding program even if their appearance is slightly poorer than that of others.
When the chickens you have left reach a year in age and you are ready to set up your breeding pens, look over, weigh and check your birds very carefully, and choose only the best as breeders. Keep second-best roosters as spares and second-best hens. There’s always a chance of a mishap, so it’s important to keep an adequate number of spares.
By diligently using a standard, by selecting only your best birds as breeders and by following a clear-cut breeding plan, you can gradually improve your flock, bringing them increasingly in line with your goals. If you’re able to make headway each year, then your birds will become better and better suited for your climate, your environment, the way that you raise them and the reasons you raise them. And they’ll also develop increased resistance toward disease. There will be difficulties along the way. This is not a fast process, but something that requires patience and steady care and attention.