Whether you have animals for meat, milk, or eggs, you need the healthiest livestock. After Doomsday, breeding your animals, while avoiding inbreeding, is going to be a lot more complicated.
This is especially true for milk animals. They must be bred to keep them in milk, and you may be keeping more of the children to provide more milk to your family as other food sources become scarce or unavailable. If you only have one male, suddenly you’re breeding a daughter and a father. Is that okay?
For strictly milk or meat purposes, yes, but if you expect to use the children of the pair as breeding stock themselves, then it may not be. Don’t think of yourself as tied down to any specific rules – think of the quality of the animals themselves.
For example, do the father and daughter share an obvious negative trait? Breeding them will amplify that trait, but the same goes for positive traits. Sometimes, animals are inbred intentionally to strengthen a favorable trait in their “line” or family.
Whatever you do, avoid full sibling breeding, which is breeding a brother and sister who had the exact same parents. Sometimes, this is done but only to see precisely what traits the breeder is working with. Those offspring are never bred themselves. Half sibling breeding is much more common and safer.
There are sustainable breeding programs you can do yourself. Let’s discuss an example with chickens: start with three unrelated roosters and, at minimum, six hens who are also not related to the roosters (preferably not even closely related).
Before Doomsday, collecting such animals is not difficult, and it may encourage you to pick from the best of several different chicken farmers’ stock. Don’t go too different, especially with various breeds, as it’s possible you’ll get the worst of each breed instead of the best.
You divide the hens into three family groups with one rooster each. You breed each hen with their rooster, but when the daughter hen becomes an adult, you shift her to another family. This way, the young hen is bred to an unrelated rooster.
When this young hen has a chick, that chick is shifted to the third family. When the chick becomes a hen, her rooster is also completely unrelated to her. By the time you get to a fourth generation, the rooster of your first family is likely the son of the original rooster and likely from a hen to which your fourth hen is unrelated.
Adding a fourth family would just add another generation into this cycle, which is unnecessary and a little too much for most to want to keep track of. If you keep track of the family tree, breed your best birds, and cull those with obvious defects, this should be enough to avoid in-breeding problems.
Technically, this breeding program will sustain all kinds of stock animals so long as you can maintain three breeding males. That isn’t always ideal with large livestock – three bulls can be a lot to take care of, especially after the SHTF – but three male rabbits (bucks) are doable, and three male goats (also bucks) are probably within the realm of possibility for you.
For larger animals, it’s good to have a neighbor who you can trade or barter with for new animals even if it’s just every three years. For example, with cattle, you can breed a daughter to a father, but probably should not breed the daughter of that union with the same male. The male would then be the father, grandfather, and great-grandfather, which is very dangerous territory.