Animal husbandry

Animal husbandry is the branch of agriculture concerned with the human practices of raising captive or domesticatedanimals for harvesting valuable animal products or to train animals to provide labour or services. It involves the day-to-day management, feeding, nutrition and health, selective breeding, assisted birth, grooming, marketing and harvest of products such as meat, milk, eggs, fibre and hide of primarily domesticated terrestrialmammals (cattle, sheep/goats, horses, pigs, etc.) and birds (i.e. poultry, mainly chicken, ducks and geese) collectively known as livestock, although the practice can be extended to various reptiles (e.g. crocodile, snake and turtle farming) and amphibians (e.g. frog farming) — collectively known as herpetoculture — and insects (e.g. beekeeping, sericulture, maggot and cockroach farming) and worms (e.g. earthworm and leech farming), as well as the cultivation of aquatic animals (aquaculture) such as fish, crustaceans (e.g. shrimps, crabs, crayfish and lobsters), molluscs (e.g. clams, oysters, abalones, geoducks and potentially coleoids) and echinoderms (primarily sea cucumbers).

Animal husbandry has a long history, and was an important part of the human evolution from nomadichunter-gatherers to agrarian/pastoralist societies that are either sedentary or semi-nomadic. Human domestication of vertebrates first started with taming of dogs more than 17,500 years ago, preceding the Neolithic Revolution, which started around 13,000 BC with the artificial cultivation of the first crops and tame animals. In early Bronze Agecivilizations like Ancient Egypt, Sumeria, Indus and China, livestock such as cattle, sheep, goats and pigs were already being raised on farms as supplementaryproduce, while herding of grazing livestock was the dominant way of life among the nomadic pastoralisttribes and horsebackconfederacies of Inner Asia and northern Africa. Major changes took place in the Columbian exchange, when Old World livestock were brought to the New World, and then in the British Agricultural Revolution of the 18th century, when livestock breeds like the Dishley Longhorn cattle and Lincoln Longwool sheep were rapidly improved by agriculturalists such as Robert Bakewell, to yield more meat, milk and wool. In the contemporary era, a wide range of species, particularly those from the genera Bos , Ovis, Sus, Gallus and Anas, are raised commercially in large quantities for slaughter by the meat industry, to provide eggs as food or to harvest milk for making dairy products. Less common species such as water buffalo, deer, llama/alpaca, turkeys, quails, rabbits and guinea pigs, as well as insect farming, are raised in selective regions of the world for the food, textile/clothing and pharmaceutical industries. Nowadays, aquaculture such as freshwater and seawaterfish farming (mariculture), shrimp farming, crab farming, oyster farming and aquaculture of sea cucumber, are also widespread due to non-sustainabledepletion of natural aquatic stocks in wild fisheries due to overharvesting and other detrimental environmental impact of industrial fishing.

Animals are also raised and trained to provide services for human activities, with the best example being the domestication of horses. The use of equine species (horses and donkeys) and their hybrids (mules) for transportation and for military tasks had been widespread in logistics, warfare and law enforcement by both agrarian civilizations and nomadic empires. The horse industry — which includes the breeding, training, grooming and trading of horses — had remained an essential economic sector up to the early 20th century, until the transport value of horses was finally diminished by the proliferation of motor vehicles following the Second Industrial Revolution. Large cattle and domestic buffalo, collectively called oxen, were also used extensively as heavy-duty draft animals to pull wagons and ploughs that demand more strength and stamina than horses, and still remain used in this day in many underdeveloped regions whose infrastructures or terrains cannot support motorization or industrial farming. Another prominent example is dogs, which have been bred, trained and used as guard animals and as hunting companions since prehistory, and dog sleds are still a popular transport option in many regions with arcticwilderness where the expansive snowfields are too difficult and/or too costly to traverse for motor vehicles and horses. Domesticated camels are also still popular in desert regions with no existing roads.

Modern animal husbandry relies on production systems adapted to the available land. Subsistence farming is being superseded by intensive animal farming in the more developed parts of the world, where, for example, beef cattle are kept in high-density feedlots, and thousands of chickens may be raised in broiler houses or batteries. On poorer soil, such as in uplands, animals are often kept more extensively and may be allowed to roam widely, foraging for themselves. Animal agriculture at modern scale drives climate change, ocean acidification, and biodiversity loss. Most livestock are herbivores, except (among the most commonly-kept species) for pigs and chickens, which are omnivores. Ruminants like cattle and sheep are adapted to feed on grass; they can forage outdoors or may be fed entirely or in part on fodders richer in energy and protein such as pelleted cereals. Pigs and poultry cannot digest the cellulose in forage and require other high-protein foods. Domesticated animals are also used to complement crops in polyculture setups such as the rice-duck and rice-fish systems.