Guinea pig in the context of "Cecotrope"

Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, fibre, milk, or other products. It includes day-to-day care, management, production, nutrition, selective breeding, and the raising of livestock. Husbandry has a long history, starting with the Neolithic Revolution when animals were first domesticated, from around 13,000 BC onwards, predating farming of the first crops. During the period of ancient societies like ancient Egypt, cattle, sheep, goats, and pigs were being raised on farms.

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. A wide range of other species, such as horse, water buffalo, llama, rabbit, and guinea pig, are used as livestock in some parts of the world. Insect farming, as well as aquaculture of fish, molluscs, and crustaceans, is widespread.

A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive/cute appearances, intelligence, and relatable personalities, but some pets may be taken in on an altruistic basis (such as a stray animal) and accepted by the owner regardless of these characteristics.

Two of the most popular pets are dogs and cats. Other animals commonly kept include rabbits; ferrets; pigs; rodents such as gerbils, hamsters, chinchillas, rats, mice, and guinea pigs; birds such as parrots, passerines, and fowls; reptiles such as turtles, lizards, snakes, and iguanas; aquatic pets such as fish, freshwater snails, and saltwater snails; amphibians such as frogs and salamanders; and arthropod pets such as tarantulas and hermit crabs. Smaller pets include rodents, while the equine and bovine group include the largest companion animals.

Hay is grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, goats, and sheep, or for smaller domesticated animals such as rabbits and guinea pigs. Pigs can eat hay, but do not digest it as efficiently as herbivores do.

Hay can be used as animal fodder when or where there is not enough pasture or rangeland on which to graze an animal, when grazing is not feasible due to weather (such as during the winter), or when lush pasture by itself would be too rich for the health of the animal. It is also fed when an animal cannot access any pastures—for example, when the animal is being kept in a stable or barn.

Rodents have been employed in biomedical experimentation from the 1650s. Rodent studies up to the early 19th century were mainly physiological or toxicological. The first rodent behavioral study was carried out in 1822, a purely observational study, while quantitative rodent behavioral testing began in the late 19th century. Currently, rodents are commonly used in animal testing for physiological, pathological and behavioral scientific studies, particularly mice and rats, but also guinea pigs, hamsters, gerbils and others. Mice are the most commonly used vertebrate species, due to their availability, size, low cost, ease of handling, and fast reproduction rate.

The domestication of small mammals to keep as pets is a relatively recent development, arising only after large-scale industrialization. Historically, Western society was more agrarian than today, with rodents as a whole seen as vermin that were carriers for disease and a threat to crops. Animals that hunted such pests, such as terriers, ferrets and cats, were prized.

Many small animals kept as household pets are rodents, including: fancy mice, fancy rats, hamsters (golden hamsters and dwarf hamsters), gerbils (Mongolian jirds and duprasi gerbils), common degus, common chinchillas, and guinea pigs (cavies). Non-rodents, including rabbits, hedgehogs and sugar gliders, are also kept.