Adaptivars
Adaptivars are cultivars specifically grown for rugged survival against local challenges. A landrace is whatever plants or animals are grown locally, adapted to those conditions, without deliberately selecting for refined traits the way breeds do. So some develop a style or purpose, like cider apples vs. dessert apples; but most display huge variety like Indian corn. If you do not have access to centuries-old landraces for what you want to grow in your area, you can make your own. Throw down as many types of heirloom, antique, open-pollinated seeds (not hybrids) as you can get. Test the results and save the best. What survives, after a few generations, will become your new landrace.
The same works with livestock as plants. Obtain some parent stock with features you like, preferably from several different hardy breeds. If at all possible, include some non-pedigreed mixed stock. Many farm animals breed once a year, so with rapid cycling you can do 5 generations in 5 years, which is a really good start. A few species, such as rabbits, can cycle even faster. You might want to keep your pure parent stock available if you're trying to set specific traits (e.g. weight gain, milk flavor, egg production, foraging ability) but the main goal is to get those offspring breeding with each other. Stir up the gene pool, then skim off the best results to reproduce. Here is a discussion regarding chickens.
The same works with livestock as plants. Obtain some parent stock with features you like, preferably from several different hardy breeds. If at all possible, include some non-pedigreed mixed stock. Many farm animals breed once a year, so with rapid cycling you can do 5 generations in 5 years, which is a really good start. A few species, such as rabbits, can cycle even faster. You might want to keep your pure parent stock available if you're trying to set specific traits (e.g. weight gain, milk flavor, egg production, foraging ability) but the main goal is to get those offspring breeding with each other. Stir up the gene pool, then skim off the best results to reproduce. Here is a discussion regarding chickens.