The Havanese breed is fortunate to have retained a lot of biodiversity or allelic richness. Not only that, their genetic diversity is well distributed. In order to preserve that high level of healthy diversity, Havanese breeders can rely more heavily on breeding for low homozygosity than most breeds, by using measures of inbreeding like IR (internal relatedness). They should also plan litters with an average OI (outlier index) around the breed average. What is the outlier index? It’s a measurement on BetterBred that tells you how typical or atypical a dog is in relation to its breed. When the average OI for a breed is high, this means that there isn’t a single specific genetic bottleneck and that most of the genetics of the breed are not very typical or atypical. These breeds tend to be healthier with less breed specific disease.

The Parents

Obviously, selection for breeding mates involves more than genetic diversity. We also want the type, temperament, drive, pedigree, etc. in our resultant puppies, just as we always have before.

This is the sire. Let’s look at the key points:

the handsome sire

The DLA: One of his DLA haplotypes is one of the most common in the breed, the other is less well represented in the population.

According to UC Davis, the most common DLA haplotypes in this breed are: 1016 (21.6% of the testes alleles), 1054 (11.8% of the testes alleles), and 1115 (11.6%  of the testes alleles) and 2003 (22.4% of tested alleles), 2022 (11.6% of tested alleles) and 2066 (18.7% of tested alleles). The rest of the DLA haplotypes in the population are less well represented. So, when all else is equal in a breeding, I might look for a mate with the less well represented haplotypes in order to preserve them in the breed. Once a haplotype disappears from a breed, they can only be restored by an outcross to another breed.

Outlier Index (OI): His OI is a little below breed average. As this number drops, a breed is breeding towards a genetic bottleneck, or genes that are represented by the majority of a population. The OI of this breed is at a good level, so breeders with individual dogs that have lower than breed average OI can easily raise them in their puppies by looking for mates with higher OI.

Average Genetic Relatedness (AGR): I fondly call this the “more breeding mates” measurement. If you select for a lower AGR, you will have more unrelated options for your potential breedings. This tells us how closely a dog is related to other dogs in our database. The higher it is, the more dogs he is related to. He has an AGR of .06, which is higher than breed average. This means he is related to more dogs in the database than most of the Havanese in the database.

Internal Relatedness (IR): And finally, the inbreeding estimate. He has a below average IR value, meaning he is very outbred.  A high inbreeding measurement would be above .15, according to Dr. Pedersen.

This is the dam. Let’s look at the key points:

the stunning dam

The DLA: Similar to the sire, she has one fairly common DLA types and one that is less common for the breed.

According to UC Davis, the most common DLA haplotypes in this breed are: 1016 (21.6% of the testes alleles), 1054 (11.8% of the testes alleles), and 1115 (11.6%  of the testes alleles) and 2003 (22.4% of tested alleles), 2022 (11.6% of tested alleles) and 2066 (18.7% of tested alleles). So, when all else is equal in a breeding, I might look for a mate with the less well represented haplotypes in order to preserve them in the breed. Once a haplotype disappears from a breed, they can only be restored by an outcross to another breed.

Outlier Index (OI): Her OI is a little below breed average. As this number drops, a breed is breeding toward a genetic bottleneck, or genes that are represented by the majority of a tested population. This can tend to concentrate disease genes as well. The OI of this breed is at a good level and this will be easy to raise in the next generation by breeding her to a dog with higher than breed average OI.

Average Genetic Relatedness (AGR): I fondly call this the “more breeding mates” measurement. If you select for a lower AGR, you will have more unrelated options for your potential breedings. The higher this number, the more dogs she is related to. She has an AGR of .04, which is higher than breed average. This means she is related to more dogs in the database than the most of the Havanese in the database. This may change as more of the population is sampled.

Internal Relatedness (IR): And finally, the inbreeding estimate. She has a below average IR value, which means she is slightly less inbred than the typical Havanese. A high inbreeding measurement would be above .15, according to Dr. Pedersen.

So, the next question is, how do they look together?

The Litter Prediction

The predicted litter was a category 7 breeding. Categories range from category 10 (unrelated) all the way to 1 (identical twins.) We generally recommend Category 6 and above, because when you go to the lower categories the level of inbreeding will be much higher and the genetic distance between the potential sire and dam will be tighter. We typically recommend running a test breeding to ensure that the predicted offspring will not have many potential puppies fall above the high threshold for inbreeding, which is generally considered to be around .15 IR. Now, there may be instances that you would breed for a higher IR, especially if you are a member of a bottlenecked breed and have a very uncommon dog/bitch. Why? Because those genetics are underrepresented in the population and could be easily lost through genetic drift, so at times a low IR may be sacrificed in order to maintain a line and the genetics (as long as the line is healthy). However, in this breed, they are well distributed with a lot of biodiversity, so can rely more on maintaining low inbreeding rates in their offspring while selecting for health and breed type.

What do you see when you look at this predicted breeding?

The Key Points

Outlier Index (OI): The predicted range of this litter is .14 to .47, so puppies could fall anywhere from far below breed average to well above it. The lower this number, the closer one might be breeding toward a potential bottleneck within a breed, though the breed average for Havanese indicates no current breed-wide bottleneck. The variation in predicted values is because each offspring will receive different genetics from the sire and dam. Each sire and dam has common, neutral, and uncommon genetics in comparison to the rest of the breed. The average for this breeding is .28, which is below breed average. The percentage of puppies falling above breed average is not very high; you can see in the image to the left that .714% of the likely litter would fall at .38, which is the breed average for Havanese.

Internal Relatedness (IR): The IR range for this breeding goes from very outbred at -.26 to very inbred at .30. However, when you go to the summary, you can hover over the graph and see just how many will fall in the highly inbred range of .15 to .30. It is a very small percentage of the litter that would possibly fall this high. For example, the likely percentage of the litter that will fall at .14 is .714% (you can see this in the image to the right).

DLA: This breeding would produce 25% of puppies with two atypical DLA haplotypes, 50% will inherit one typical and one atypical, and 25% would inherit two common DLA haplotypes. This is not necessarily bad (read about DLA uses here), but when all things are equal, it may be good to keep the puppies with underrepresented DLA types.

The Offspring

This is the tested offspring, “Heidi” Lossombra’s Little Runway Star.  Let’s look at the key points:

DLA: She was one of the puppies to receive one underrepresented DLA haplotype and one of the most common (remember it was predicted that 50% of the litter would receive one typical and one atypical).

Outlier Index (OI): Heidi’s OI fell just below the predicted average for this test breeding, which was within the predicted litter range. It means her genetics are more typical for the breed than the other Havanese in the database, but does not indicate health or quality. If the breeder wants, they can try to find a suitable mate that meets their desire for type, temperament, drive etc that will help raise the next generation’s OI in order to prevent breeding towards a bottleneck. However, since Havanese are so diverse, this is less important than in other breeds that have lost diversity, because it is easy to find dogs with different genetics to breed to in the Havanese breed.

Average Genetic Relatedness (AGR): This is the “unrelated breeding mate” measurement. The higher this is the less dogs in the database are unrelated to your bitch or dog. Heidi’s is higher than breed average, so she will have fewer unrelated dogs in the current database than is typical for the breed. However, this may change as more of the breeding population is tested.

Internal Relatedness (IR): Heidi’s IR is above breed average, but is not terribly high. It’s higher than the average of the litter prediction, but well within the predicted range. As long as she is bred to an unrelated sire, she will produce outbred puppies in the next generation easily.

Heidi is pictured as the feature photo for this blog post. Thank you to the owners of these dogs for allowing us to use them in this post.

Conclusion

This breeding predicted outbred offspring with genetics that would be slightly more typical than the breed average. The resultant offspring fell well within the predicted values. There can be great ranges in genetics for each litter, and puppies can fall anywhere along those predicted ranges. Often we have seen that entire litters vary drastically from one another, both in inbreeding values as well as outlier index and average genetic relatedness (AGR). The choices we make with each breeding will affect our breed genetics and dynamics in future generations to come; we should be careful to select so that we lose less biodiversity to genetic drift.

Of course breeding is more than just about diversity, as we always need to pair selection for type along with selection for diversity. We cannot have one without the other, as breeding is done by passionate breeders because they love their breed, their lines, and the “family” they have created. BetterBred never suggests breeding for diversity to the exclusion of consideration of pedigree, type, temperament, drive, health etc. This is to add, not detract, from our breeding strategies.