Anyone who has ever read my breeding related articles, English or Finnish, probably knows that I heavily promote mean kinship as the ultimate tool to help in breeding of small populations. There are other complimentary tools, but most are not available to that everyday person who would just want to make intelligent choices to help their breed. It is perfectly OK to want to do this, but not want to commit to downloading and learning to use complicated software and managing large datasets.
This post is for you, a current or future breeder, or male owner. The responsibility to promote genetic diversity of the breed is on everyone’s shoulders, and there are ways to navigate this without getting too technical. I will be using longhair DS examples in this post, but the information is applicable everywhere.
You might have heard about effective population size (Ne) versus population census size (N): the actual number of animals is less important for genetic diversity than the number of animals breeding. There is a lot to understand with effective population size, but in its most simple form it represents the number of individuals that contribute offspring to the next generation. To give an example: the most recent generation (calculated with 4-year generations, 2017-2020) of the longhaired Dutch Shepherd was produced by 131 parents; 62 males and 69 females. Since 2000, on average 15% of all registered dogs have ended up in breeding. The ratio of both genders in breeding is 47% for males and 53% for females.
The formula we are using is:
Ne = 4NmNf/(Nm + Nf)
Ne = 4*62*69/(62 + 69) = 17112/131 = 131
So the effective population size for the longhaired variety would currently be 131. There are three ways to maximize effective population size:
- Increase population census size while still selecting the same percentage for breeding
- Select more dogs from each generation for breeding
- Equalize breeding male to female ratio
As the example shows, 3. is already pretty much in the bag. Actually it is so well in the bag that it makes this example a poor one. In most breeds uneven male to female ratios are one of the most damaging breeding practices out there, since it drastically reduces effective population size (you can test this by solving the equation above with 1 male 130 females: the total number of parents is still 131, but Ne is only 4!). 1. is hard to achieve, with world-wide registration numbers staying relatively even with around 23 litters a year since the late 90’s, and we all know it is simply not possible to just magic a breed into being more popular. Currently the most powerful option is 2., making sure that instead of 15% of all dogs, a higher percentage would be used in breeding.
To achieve this we need to increase the number of individual breeding animals, both males and females. In a population of relatively constant size like the longhair, it also means avoiding the excessive use of individual breeding animals, so contributions stay even and effective population size stays as high as it can be. And to make that part less easy, we always have to look past one generation. In essence a popular sire or dam can be an individual with just one litter but who then had multiple offspring making larger contributions into the population. Whenever one individual ends up in too many pedigrees, it becomes a problem. This is why looking into the second and third generation – forwards and backwards – of each dog is important as well.
And why are we not talking about inbreeding coefficient this time? Because when we are selecting our breeding animals, it is not the inbreeding coefficient we need to focus on. High inbreeding coefficient (high homozygosity) in an individual is not a problem in itself. High inbreeding in a population is a consequence of poor breeding practices, and instead of focusing on the consequence, we should focus on the root of the problem. The root is low Ne: too few breeding animals in a population that is much too small. When we solve this problem, increase in homozygosity will slow down, even if we never calculate another inbreeding coefficient again.
In the following paragraphs I will mention some ideas on what each of us can do to help. When I use the term “common bloodline”, I mean pedigrees that have over-represented dogs and/or high mean kinship. When I say “rare bloodline”, I mean pedigrees that have under-represented dogs with few offspring and/or low mean kinship.
If you are a breeder with very common bloodlines, start working on making them less concentrated. Instead of using one female from your next litter two times, use two females one time. Choose males that have not been used for breeding yet, or have dying bloodlines. If you find an individual from parents that have no other reproducing offspring, that is a great choice and useful even if those parents did not have extremely rare pedigrees. An established breeder is already more experienced and should always explore new options to diversify the breeding stock.
One thing to avoid is to suddenly pair a very common pedigree with a very rare one, since this creates a difficult situation where the only way to increase the share of that rare pedigree is to increase the share of the common one even further as well. If a breeder wants to work towards less common bloodlines, it is better done gradually.
If you are a breeder with rare bloodlines, do not pair your dogs with the most common ones. Not just because the common ones are already common enough, but because your rare bloodlines will become more related to all other dogs, and decrease their value while reducing your future options. It is not a bad thing to have dogs that look or act a little different, variety is a sign of diversity. To honor the word genetic diversity we must nurture diverse bloodlines!
There is a lot to consider when choosing which stud to use. There might be a race to use a promising young dog with an amazing pedigree, but the joy of being the first one to use him will eventually turn into a disappointment, if he is used time and time again and your breed ends up saturated with his bloodline. Unless you own the dog yourself, it is very hard to predict what will happen. When you pick older males, you can be more confident about what will or will not happen. Never use a male whose contribution is already at max capacity for the population, this is damaging for the breed and undermines not only your work, but the work of other breeders who used that stud before you.
Always be aware where your puppies are going. It is not possible to control everything, but you can attempt to keep the next generation breeding use of your dogs at sensible levels by choosing who to sell to. If someone who bought a dog from you goes all out and makes your bloodline an over-contributing one, it is going to affect your breeding as well.
Get your foundation animals from bloodlines that have as few over-contributing individuals as possible. You will have more options in your own selection and you might even end up creating something unique. But be careful of fashionable choices! It can be difficult to spot a future over-contributing pedigree as a newcomer, but you can try. Sometimes the best place to start proves to be a regular dog from a small breeder from a relatively uninteresting pedigree – uninteresting does not always mean bad quality.
To ensure a good start for your breeding, it might seem like a safe option to use a male several others also used. But dare to be brave! Always consider if that popular sire has brothers or nephews that might be a better option. And if none of them are suitable for breeding, are the genetics really superior enough to warrant even more use?
Be very careful when you give your male for breeding. Realize that some litters are more likely to explode with second generation growth than others – the breeder, the pedigree of the female and who the puppies were sold to will influence this. When you work with a breeder who protects their bloodlines your male might not become the next influential sire of the breed, but can instead be a part of healthy breeding practices and a valuable future bloodline. Notice here that valuable is not the same as wide-spread!
Wait as long as possible between two breeding uses to have a better idea on what might happen with the first one. Ideally, choose females with different bloodlines from each other to avoid creating pedigrees that resemble each other. Your responsibility is as large as the breeder’s: at some point you are going to have to tell inquirers that some other male should be used instead.
Almost any male, especially a good one should have at least one litter. One or two more if he is an especially great one in all aspects. But always keep in mind there is a limit – no matter how good your male is it does not warrant overuse. To ensure his quality will be passed on, instead of breeding more litters, focus more on quality control of the females. A good guideline is never to let the contribution of a single male rise higher than the number equivalent to 5% of births in one generation. At the time of writing this, this number is 33 puppies for a longhaired Dutch Shepherd.
What I want to emphasize here is that it is impossible to only make perfect choices. Just like with health or character, not every combination is a success for boosting diversity either. And when all aspects of selection are taken into account, there simply are no choices that are correct on all fronts.
HOWEVER. We all have the power, and the responsibility to tend to our breed’s genetic heritage. It is in our hands, and in our hands only, and the future generations depend on the choices we make today. No breeder has the moral right to keep exploiting an overused bloodline, if it is going to damage the breed long-term. This can mean some sacrifices, like retiring a female early, selecting a different male, or refusing to sell a puppy to someone with no care for the breed. Inherently we are all breeding for the future of the breed, whether we want it or not.
This post was written to support my website HH DASHBOARD – Tools for Breeders of the Longhaired Dutch Shepherd Dog, where you can find relevant data of the world-wide population of the longhair: offspring numbers in three generations, mean kinship, coefficient of inbreeding, and more. Updates coming soon. 🙂