A landrace is a group of genetically related animals unique to a given geographical area. Landraces come about over time as animals within the area interbreed for many generations with relatively little outside influence. The fact that all of the animals within the population descend from the same set of ancestors, whether those ancestors came from one source or many, creates a certain level of genetic uniformity. This makes it possible for an observer to distinguish each landrace from other breeds and landraces.
The environment is the major factor that shapes the landrace. If a given animal is not suited to local conditions, it probably will not thrive and produce offspring, eliminating its genes from the population. Instead, other animals that can thrive in those conditions will produce the next generation.
Examples of local conditions that landraces adapt to include:
- Abundance or scarcity of water.
- Natural food sources.
The Role of Man in Shaping Landraces
Even though nature has the most say about the gene pool of a landrace population, humans also play a role. Indeed, this element of human intervention is part of what separates a landrace from a feral population.
People shape the genetics of a landrace both passively and actively. Passive selection occurs when humans alter the environment or its natural effect on animals through various management practices. These practices can include:
- Providing shelter.
- Providing feed or supplements.
- Restricting animal movement to specific areas.
- Doctoring sick animals.
- Assisting with animal births.
We often consider these practices to be part of good stewardship of our animals, and rightly so. However, the fact remains that most management practices alter the course of nature and enhance the chances of survival and reproduction for animals that otherwise might have left little genetic legacy.
What some animal breeders overlook is that active selection has played a role in shaping many landraces, as well. The history of many landrace breeds show us that humans have specifically chosen certain animals to reproduce due to their desirable traits and have culled others due to their undesirable traits. Sometimes the entire landrace population is shaped in this way, while in other cases one family of breeders has simply established their own bloodline within the broader population.
Humans have actively selected some landraces for:
- Working ability.
- Specialized purpose.
Landraces Vs. Standardized Breeds
This brings up an important question: If landraces have been actively bred for appearance and production, then is there any difference between a landrace and a standardized breed?
The simple answer is yes.
Note the factors that most landraces have in common:
- Concentration in a specific geographical area.
- Limited numbers.
- Genetic isolation primarily due to geographical isolation.
- No formal breed association overseeing registry.
- No written standard.
Compare and contrast this with the characteristics of a standardized breed:
- Broad geographical distribution.
- Numbers varying from extremely rare to extremely popular.
- Genetic isolation primarily due to attention to pure breeding.
- Registry and promotion by a formal breed association.
- Written standard of desirable characteristics.
However, now that the Internet has made promoting breeding animals to distant buyers possible, the lines between landrace and standardized breed have become a little more blurred than advocates of either would perhaps prefer.
At present, there is still enough difference between a landrace and a standardized breed to say that the landrace is typically the more genetically diverse of the two. There are exceptions:
- A landrace breed teetering on the brink of extinction may lose its genetic diversity through population depletion and subsequent inbreeding.
- A standardized breed may have maintained its original genetic diversity through the preservation of several distinct bloodlines.
Examples of Landraces
Breeds that can still be classified as landraces include:
- Florida Cracker cattle.
- Pineywoods cattle.
- Randall cattle.
- Rocky Mountain horses.
- Spanish Colonial horses.
- Choctaw hogs.
- Ossabaw Island hogs.
- Spanish goats.
- Icelandic chickens.
- English Shepherd dogs.
However, a landrace does not always have to stay a landrace. If a group of breeders decides to pursue more formal breeding methods, the landrace may become the basis of a standardized breed. Examples of landraces that have become standardized include:
- Corriente cattle.
- Lineback cattle.
- Texas Longhorn cattle.
- Dutch Landrace swine (ironically).
- Mulefoot hogs.
- Tennessee Fainting goats.
- Florida Cracker sheep.
- Navajo-Churro sheep.
- Australian Shepherd dogs.
- Border Collies.
- Carolina Dogs.
An Introduction to Heritage Breeds
Excellent book with basic information on landraces and how to preserve their genetics.