Hello. I’ve put this topic in the chicken section but it could be relevant to any animal.
I was chatting to the boss at work the other day and was shocked to learn that he doesn’t care about inbreeding in his flock of sheep. He has 10 acres (not permaculture) and only replaces his ram every 3 or 4 years. He doesn’t care about inbreeding between ram replacements.
I was thinking about this and realised that we raised chickens when I was young and I have no recollection of ever replacing the rooster despite many years of breeding. It’s going back a fair few years now so my memory could be wrong but it appears that we were inbreeding our chickens as well. (Or my parents were getting rid of the hens without me noticing).
So, Two questions: 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?
I have no experience with animal.breeding so take this with a cup.of salt.
Basically, fears about inbreeding are (I think) often overblown. There is not any inherent harm that I've ever been shown from inbreeding, it is just that you have no way to.breed out any traits you don't want. Inbreeding has been central to strain/variety formation in plants and animals since forever. Assuming healthy and vigorous starting population, the worst you are doing to yourself by inbreeding is creating a genetic bottleneck that limits the total scope.of traits that are ever available to you
Some elements of farming, we actually want to inbreed as it helps solidify traits in the flock. But in many situations, a wide genetic variety is a huge bonus.
With sheep, I keep a breeding flock, but I don't always keep lambs every year. That way, I can keep the same ram several years in a row without inbreeding, because very few if any of his offspring are kept. However, in some situations, it's not only okay, but desirable, to have up to 3 generations of inbreeding in sheep if the results have the traits you are trying to increase in the flock. So 3 years with the same ram is pretty standard, 4 years is pushing it but so long as there are no obvious signs of genetic defects, it's okay. This goes for most farm mammals.
With chickens, I finally settled on a barnyard mix, with about 20 different breeds of chicken starting, and adding a few more breeds as time went on. That way the genetics are varied and I don't have to worry about importing a rooster every few years.
With ducks, I have half a dozen breeding ducks and two drakes. These are steady from year to year, only replacing one if another one dies. When we first started, we had the girls from one line from out of town, the two drakes were from separate parts of the province. When the drake dies, we will usually import one from another farm, but sometimes, if we feel the genetic variation is still good within the flock, we'll keep a son. I keep a close eye on genetic defects and the ratio of pigeon toe vs waddle toe offspring as these are the two primary traits of our original drakes.
Do I care about inbreeding? I am aware of it. I'm not afraid of it as it makes a good tool for improving qualities in a flock, but I am careful to observe any defects that are obviously genetic and cull accordingly.
A few things to think about when bringing in new replacements.
1. local isn't always good. With sheep and goats, I find that most breeds only have two male lines and many of these are crossbread. So getting new livestock from within driving distance isn't always a guarantee you'll get new genetics. I almost bought a ram this year until I found out it was closer related to my girls than the one we just had.
2. Every new animal that comes onto your farm is a chance to destroy the farm. There are some seriously bad STDs, especially in sheep and goats, that can mean culling the entire flock. Or worse, having the government take an interest in the culling - so that you don't get the money from the meat sales and well, I don't really want to go into that.
So far, with our chickens, it's a non-issue, because hubs doesn't want a roo. With the goats, I have some issues right now, because I'm working toward breed development and advancement. If I allow my buck to breed with his daughter, the breed genetics classification stays at her level (f2). So, we're getting an f2 buckling, this month, to advance to f3 genetic classification. Beyond that... well, time will tell.
We just purchased all our ducklings as a straight run, so I've no clue if any are from the same lineage, and they're only 4 weeks old, at this point. Most will be in the freezer by the end of this month, but in keeping a drake and 2 ducks? Who knows. But, we only want them for eggs and meat - not sales. So, we will likely replace the drake every few years, until the ducks stop laying, then we will replace them, instead. I think.
The only thing...more expensive than education is ignorance.~Ben Franklin
my current kittens are product of brother and sister, out of 4, 1 seemed very slow doncha no a hawk got it probably fed to its chicks, the three remaining all males are fine rat catchers. I think all the feral cats in the area have been got, well see what happens when momma gets in heat again.
This is correct; however, in livestock, inbreeding is often done in an effort to identify these hidden recessives, which allows the breeder to cull the undesirable gene(s) from the herd and work towards having a bloodline which is homozygous for the desirable genes.
At the same time, outcrossing to an animal from a different line doesn't necessarily lower the chance of getting a "double recessive."
For instance, when I first started breeding rabbits I occasionally had cases of malocclusion show up in my litters, so I culled the stock with bad teeth and the stock that produced bad teeth and the issue was resolved within a few generations.
3-4 years later I brought in a new, unrelated buck and bred to the girls. The second generation after bringing him in I started seeing cases of malocclusion, again, in the animals descended from him. Had I not linebred closely, I would have had the gene circulating through the herd again, just waiting for the right opportunity to show up. While some may feel it's okay when the maladaptive genetics stay hidden, I prefer to identify them and cull them from the gene pool before they get spread out across the herd. Additionally, I don't want to potentially sell an animal that carries something undesirable to someone and end up damaging their line's gene pool by introducing the recessive.
It's definitely important to monitor for receive unwanted traits.
The big problem with pure breeds, which is especially evident in dogs and the kind of goats I have, is that they have an hourglass shape genetics. The goats, for example, at one time went down to a population size of SIX. That's six goats and from those six goats, all the goats of that breed in Canada are descended. So even though we have a few hundred now, and there is a second billy-line (boy descendent line) on the far side of the country, this narrow spot in the genetic history makes inbreeding very dangerous. And yet, to maintain the breed, we still have to inbreed to some extent - although there is a method where you grade-up (you bring in a goat of a different breed, then inbreed the decendents back into the breed standard.
Choosing starting genetics that are as varied as possible leave more leeway to inbreed without genetic defects. Like my chickens for example. So long as I get vast variety in the offspring, I feel confident that I can keep the flock closed (no outside inputs) for probably 10 or 20 more years. With my sheep, if I want to buy a ram, I need to be careful to choose a ram-line that isn't too closely related to my current sheep as I have a few double descendants from my last ram.
In the wild, inbreeding is common and used to better survival in most herd species. Take a bull elk that that will be dominant enough to mate with often up to 3 generations of his offspring. Even when replaced by a young aggressive bull it will often be one of his own sons which will still keep the inbreeding intact. This gets repeated over and over through multiple generations.
"may your experience be fruit for all those who follow"
One thing to remember, though, is that wild animals usually don't survive if they have dangerous recessives. Unlike livestock, no one is going to try to keep them alive if they're weakened. The vast majority of inbred recessives that might be dangerous are sorted out within a few generations as the animals die off before they have offspring.
With animals that are bred for specific traits, they're more likely to be catered to and medicated/treated until they can pass on the damaged genes. Take the elk vs a herd of cows--an elk that can't push out her calf will die. Period. A human will pull the cow's calf, then go ahead and do it again as often as necessary, and keep that cow's descendants who then have the same problem. It becomes normal.
Zone 5b/6a, alkaline soil, 12 inches of water per year. For now the goal is a water independent urban homestead with edible landscaping and food forest.
One should never get that attached to homesteader livestock/poultry that they can't cull the poor traits. What nature can't do under these conditions we must.
"may your experience be fruit for all those who follow"
posted 1 month ago
I think that continuous inbreeding with little to no culling is certainly dangerous and likely to create problems. What I was trying to express was that the simple act of inbreeding isn't a guaranteed source of problems. As long as its paired with a willingness to cull and careful observation I wouldn't be overly stressed about some inbreeding
When it comes to selecting breeding stock, culling the defective ones is one option but for me, I keep this as a last resort. The big point is to prevent them from breeding, so what happens to the ones that shouldn't be bred depends on the farmer and their situation.
If the defect doesn't affect the quality of life, there can be quite a bit of value to the ones that shouldn't be bred. I keep a couple of canaries in each flock - animals that have weak genetics and are more susceptible to illness. If there's an illness or parasite load in the flock, these animals get sick quick and hard. They show illness long before the others and by watching my canaries daily, I can see when it's time to give a close health-check on the other members of the flock before the issue gets bad.
Even if they aren't breeding, animals can still serve their function - grow wool, mow lawn, produce eggs, eat slugs, whatever the animal does best - on the farm. If there isn't enough room on the farm, one can sell it to urban farmers who won't be breeding the livestock. They just want two chickens to lay breakfast omelettes or a couple of old sheep for mowing the lawn.
Human selection can be so much kinder than natural selection. Natural selection is ruthless in the way they rogue out the undesirable characteristics, but humans have kindness. We can simply choose who to breed and not breed.
If a ewe cannot push out a lamb unaided, I still help her. But then I think very hard about breeding her again. Was it something wrong with the ram (too large a head?) or something wrong with the diet (probably the most common issue with birthing in my part of the world), or something wrong with her genetics. Is it time for her to go to the retirement flock up the road?
If I ever had livestock, I'd be obsessed about pedigrees for sure. I know how much damage inbreeding did to dogs; although it wasn't inbreeding per se, but rather the purpose (breeding for looks and shows, not for function).
I used to have pet rats and I kept their pedigrees even after they died :D four generations!
It's really such an interesting topic.
I only have plants, and from the generations that repeat (mostly pumpkins) - I collect only the seeds from the healthiest and most tasty fruit, and I exchange seeds with other permaculture gardeners in the area. So they're different each year but also better and more adapted.
There are a lot of good and thought-provoking comments here!
When I think about inbreeding, I think of the permaculture teachers who encourage the planting of trees from seed rather than the commercial practice of grafting everything. One of the issues in our forests is that some were planted not just as mono-cultures, but with seeds from an extremely narrow group of parent trees.
I will also add about living on an Island - getting a divergent blood-line can be hard. I've been trying to get new Khaki-Campbell ducks for at least 3 years without luck. The symptoms are subtle, but livability in young is the most obvious - too many die in the shell or during hatch. I finally decided that this year I'd try crossing with a breed with Khaki in them. It may give me some healthier ducks, but I have no idea where to go from here next year. It's complicated because female khakis all look the same pretty much, and my success with leg bands is less than stellar. I've got two young females in the adult group, and one has lost her band after only a month! All we can do is try.
I've been taught that in the wild, predators prey first on the weak, which replaces the safety system that discourages inbreeding. Along the North American East Coast there are increasing cases of wasting disease in deer and I suspect at least one factor is the shortage of predators. Unlike wolves, when humans fill the predator roll, they often kill the "biggest and the best" and avoid an animal that looks sick.
One domestic example is from an acquaintance that breeds "pug" dogs - the puppies are all delivered by C-section because their heads are too large. Nature would not put up with that crap!
A second domestic example is how humans are incubator hatching so much of our poultry that we're at some risk of eggs not being naturally successful. That's fine so long as the power stays on, but it also does a disservice to the animals. I find that roosters and drakes that are raised by "real moms" are much more respectful of the hens/ducks and will actually perform a mating ritual. I've culled roosters I've been given that were incubator/human raised if they demonstrated behavior akin to "rape". (I have a very deep-seated internal moral objection to "rape" - I am who I am...)
Bringing it back to the Farmyard, with veterinary medicine, Nature is a lot less involved with selecting which animals get to breed and don't.
So it's up to the farmer to choose which traits they want to keep in the flock or herd. It's very important to be aware of the ancestry and any genetic bottlenecks that might have occurred in the lines.
I find it very interesting that in mammals and birds in the wild, many species have social or other methods of preventing inbreeding, sometimes at the cost of number of offspring. This implies to me that, although not always immediately harmful, there is strong selection pressure against extensive inbreeding.
Typical social methods are either dispersal of young, avoidance of known kin, and other methods include avoidance of animals with similar phenotypes.
On the farmyard- most long term farmers I know take great care to swap in "new blood" from afar. I have one friend who talks about trading barn kittens with distant farms to prevent genetic defects and the more insidious "lack of vigour".