Animal genetic resources for food and agriculture are a subset of genetic resources (defined by the Convention on Biological Diversity as "genetic material of actual or potential value") and a specific element of agricultural biodiversity. The term animal genetic resources is often used to refer specifically to the genetic resources of avian and mammalian species used in or potentially used for food and agriculture purposes. The term "animal genetic resources for food and agriculture" is often shortened to "farm animal genetic resources" or simply "animal genetic resources" and sometimes referred to as "livestock biodiversity" or simply "livestock diversity".
Animal genetic resources can be embodied in live populations or in conserved genetic materials such as cryoconserved semen or embryos. The diversity of animal genetic resources includes diversity at species and breed and within-breed level. There are currently known to be some 8,800 different breeds within 38 species of birds and mammals that are currently used for food and agriculture. The main animal species used for food and agriculture production are cattle, sheep, goats, chickens and pigs. In the livestock world, these species are often referred to as "the big five". Some less-utilized species include the dromedary, donkey, bactrian camel, buffalo, guinea pig, horse, rabbit, yak, goose, duck, ostrich, partridge, pheasant, pigeon, and turkey.
The wide number of livestock breeds and the genetic diversity within them mean that animal genetic resources have a substantial value to society. The different breeds provide a wide range of animal products and services for the benefit of humankind. The diversity of animal genetic resources allows livestock to be raised successfully in a diverse range of different environments and underpins the supply of a range of different products and services: from meat, milk and eggs to fuel, manure and draught power.
Diversity also allows the flexibility to change breeding goals if needed and emphasize alternative traits in response to changes in markets or other conditions. For example, while the Holstein Freisian Cow is widely used for its whole milk production, if cereal feed availability or demand for low-solid content milk changes, there may be a decrease in the advantage of breeding Holstein cows. Different breeds produce specific wool, hairs and leather for clothing, carpets and furniture and are often the basis for traditional garments.
Local breeds that were developed by a given community often have a huge cultural significance for that community. Livestock are often a source of wealth and are critical for its maintenance. They appear frequently in art and often play key roles in traditional customs, such as religious ceremonies, sporting events and weddings. Cultural ecosystem services also create significant economic opportunities in fields such as tourism (including, in the context of food and agriculture, farm holidays and visits to areas with historical or scenic farming or forest landscapes) and recreational hunting.
Breeds that have been developed primarily through natural selection have effectively evolved with their environments and usually provide ecosystem services, such as landscape management, vegetation control, and promotion of biodiversity, that are critical for maintaining those landscapes. For example, the Engadine sheep, which were near extinction in the 1980s, today help to preserve centuries-old grassland in the Alps by eating invasive shrubs. Grazing livestock also help sequester carbon by removing plant material and encouraging regrowth and thus the movement of carbon from the air into soil organic matter.
Greater livestock diversity allows humans to be better prepared to meet future challenges, such as climate change. Having access to a range of diverse livestock traits may allow for greater ability to cope with harsh climates and emerging diseases. Animals with unique adaptive abilities, such as resistance or tolerance to diseases and pests, or ability to thrive on poor feed and cope with dry or hot climates can help humans be more resilient to changes in climate. Within breeds, greater genetic diversity allows for continued selection for improving a given trait, such as disease resistance.
"From a formal economic perspective, animal genetic resources can have various different types of value for conservation. These values can be categorized as followsDirect use value – results from benefits obtained from the utilization of animal genetic resources, such as the production of milk or meat.
Indirect use value – results from the provision of support or protection to other activities that produce benefits, such as through the provision of regulating and supporting ecosystem services (e.g. cycling of soil nutrients, seed dispersal, fire control).
Option value – results from the potential benefits of having a given resource available for the future; for example, having genetic variability available that can be used to respond to market and environmental changes.
Bequest value – results from benefits that might be obtained from the knowledge that others may derive benefits from the animal genetic resource in the future.
Existence value – results only from the satisfaction of knowing that a given animal genetic resource exists, even if no other type of value can be derived from it.
Increasing the direct use value will contribute to the economic sustainability of a breed and therefore to the potential for successful conservation activities."
Despite the importance of animal genetic resources and their diversity, their diversity has been continually decreasing over time. For example, the Pantaneiro cattle of Brazil are at risk of extinction. One of the greatest threats to livestock diversity is pressure from large-scale commercial production systems to maintain only high-output breeds. Recent molecular studies have revealed that the diversity of today's indigenous livestock populations greatly exceeds that found in their commercial counterparts. Some other major threats to livestock diversity include climate change, inappropriate development of policies and management strategies, disease outbreaks, armed conflict and various types of natural disasters and emergencies.
Climate change and its impact on livestock is being studied. Changes in climate will have an impact on livestock and food production in many ways. In Africa, different regions are predicted to experience different changes in weather patterns. For example, parts of Madagascar and Mozambique are predicted to have a drier than average rainy season, while just north in parts of central Africa, a wetter December–January season is expected.
Some major disease threats that livestock currently face include, rinderpest, foot and mouth disease, and Peste des petits ruminants (PPR), also known as sheep and goat plague.