Tom Pivac wrote: Do you care about inbreeding in your farm animals (or you do for some types but not for others) and what steps do you take to prevent inbreeding if you do? Cheers.
That is a very good question. My personal opinion is that the best animals I've ever had came from crossing purebreds from 2 different breeds. So, for example, my favorite dog was 50% Border Collie and 50% Blue Heeler. Doing this provides hybrid vigor and an outcross that greatly reduces any weaknesses caused by inbreeding in the original 2 breeds.
I did the same with horses. When I no longer bred registered Thoroughbreds (TBs) for racing, I outcrossed them to AQHA (quarter horses / QHs) so that my younger horses are 50% TB and 50% QH. In so doing, I retained the endurance and quality of the TB side, but greatly improved their feet, made them easier keepers, and gave them strength to do work around the homestead should that become useful in the future.
Many horse breeds are very inbred, but only through the best lines. TBs we typically avoid inbreeding closer than 2x4 or 3x3 because close inbreeding often results in much smaller offspring that are potentially unsound for the purpose intended. That close they tend to be dominant breeding animals and when it works, outstanding performers.
On the other hand, QH breeders often breed extremely closely. Daughter to sire (father) matings are common, especially in lines where people are trying to increase or maintain very high inbreeding co-efficients. The lines that inbreed are typically working horses rather than racing horses.
And QHs are often less inbred to start with than TBs which can trace their lineages back to the 1800s. That said, most QHs carry TB bloodlines if you go back far enough. They just don't have records because the AQHA is a young breed of horse.
When I decided to get ducks, I am doing the same thing. My drakes (males) are American Pekin aka Long Island Pekin and Buff. When I acquired more females, I bought Silver Appleyard, Buff, Rouen and Khaki Campbell -- primarily Silver Appleyard. All of these breeds were developed from the same duck lines (Ayershire and Mallard principally), but the ducks I have would not be related to each other (except 1 Pekin female).
I thought horse color genetics was complicated; duck color genetics is even more complex and the available tools aren't as useful. In case anyone is interested:
BUFF
The buff ducks are a result of a cross between Indian Runner, Rouen and Aylesbury ducks.
PEKIN (American Pekin is actually a Long Island)
original Pekins descended from mallards and were upright like runners. American Pekins were developed by crossing with Aylesbury ducks.
Silver Appleyard
Created by crossing Rouen, Pekin, and Aylesbury. Appleyards as previously mentioned are light phase restricted mallards. The restricted mallard gene (M^R) is reportedly dominant over its alleles (M+ & m^d), & was called "restricted mallard" largely due to melanin restricting action in duckling down. very young pure bred Appleyard ducklings are ususally yellow-ish with only the "mohawk" & tail showing dark pigmentation. As the ducklings age dark pigments do come through
Rouen
Also referred to as Giant Mallards, they are descendants of wild mallards developed in France
Khaki Campbell
To begin, Campbell crossed an Indian Runner that was an exceptional layer with a Rouen of good size. Later, she bred the resulting offspring with a Mallard to develop hardiness in her breed. Next, Mrs. Campbell wanted a particular buff coloration, so she added Penciled Runners to the mix. The end result were the attractive, excellent laying Khaki Campbells that we know today.
CROSSES
Pekin over Silver Appleyard
Mallard x2 / Aylesbury x2 / Rouen / Pekin x2
Pekin over Rouen
Aylesbury / Mallardx2
Pekin over Khaki Campbell
Aylesbury / Indian Runner x2, Rouen, Mallard x3 (one from the Rouen)
Buff over Silver Appleyard
Indian Runner, Rouen x2, Aylesbury x2
Buff over Rouen
Indian Runner, Rouen x2, Aylesbury, Mallard
Buff over Khaki Campbell
Indian Runner x2, Rouen x2, Aylesbury
If anyone is interested in inbreeding patterns, I'm happy to answer questions. In TBs, we intentionally linebreed one family, especially through the best females and then outcross from that family while simultaneously linebreeding another family in the same pedigree.
Studying how cattle ranchers brought in new sire lines can be useful. And I suspect that would work well with most livestock. They intentionally inbred to determine whether their breeding stock carried any negative recessive traits (so they could cull them). But then they typically outcrossed or linebred once they knew a line was solid.
When choosing breeding stock, the conformation / health / disposition of the offspring is more important than that of the parents themselves. Sometimes, a beautifully put-together mare will through bad foals and a mediocre mare will throw good foals when bred to a better stallion. I used to call those "pass-through" mares = mares whose own genetics were so weak that all her offspring resembled their sires.
Pollinator Scavenger Hunt
Number Posts (289/200)
Number Threads Started (3/100)