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Cross-fostering
Cross-fostering is a technique used in animal husbandry, animal science, Genetics, genetic and nature versus nurture studies, and conservation (genetics), conservation, whereby offspring are removed from their biological parents at birth and raised by surrogates, typically of a different species, hence 'cross.' This can also occasionally occur in nature. Animal husbandry Cross-fostering young animals is usually done to equalize litter size. Individual animals born in large litters are faced with much more competition for resources, such as breast milk, food and space, than individuals born in smaller litters. Herd managers will typically move some individuals from a large litter to a smaller litter where they will be raised by a non-biological parent. This is typically done in pig farming because litters with up to 15 piglets are common. A sow with a large litter may have difficulty producing enough milk for all piglets, or the sow may not have enough functional teats to feed all pig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Husbandry
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, 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. By the time of early civilisations such as 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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds ( taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competition (biology)
Competition is an interaction between organisms or species in which both require a resource that is in limited supply (such as food, water, or territory). Competition lowers the fitness of both organisms involved since the presence of one of the organisms always reduces the amount of the resource available to the other. In the study of community ecology, competition within and between members of a species is an important biological interaction. Competition is one of many interacting biotic and abiotic factors that affect community structure, species diversity, and population dynamics (shifts in a population over time). There are three major mechanisms of competition: interference, exploitation, and apparent competition (in order from most direct to least direct). Interference and exploitation competition can be classed as "real" forms of competition, while apparent competition is not, as organisms do not share a resource, but instead share a predator. Competition amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avian Incubation
Egg incubation is the process by which an egg, of oviparous (egg-laying) animals, develops an embryo within the egg, after the egg's formation and ovipositional release. Egg incubation is done under favorable environmental conditions, possibly by brooding and hatching the egg. Multiple and various factors are vital to the incubation of various species of animal. In many species of reptile for example, no fixed temperature is necessary, but the actual temperature determines the sex ratio of the offspring. In birds in contrast, the sex of offspring is genetically determined, but in many species a constant and particular temperature is necessary for successful incubation. Especially in poultry, the act of sitting on eggs to incubate them is called brooding. The action or behavioral tendency to sit on a clutch of eggs is also called broodiness, and most egg-laying breeds of poultry have had this behavior selectively bred out of them to increase production. Avian incubation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nest
A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic material such as twigs, grass, and leaves, or may be a simple depression in the ground, or a hole in a rock, tree, or building. Human-made materials, such as string, plastic, cloth, or paper, may also be used. Nests can be found in all types of habitat. Nest building is driven by a biological urge known as the nesting instinct in birds and mammals. Generally each species has a distinctive style of nest. Nest complexity is roughly correlated with the level of parental care by adults. Nest building is considered a key adaptive advantage among birds, and they exhibit the most variation in their nests ranging from simple holes in the ground to elaborate communal nests hosting hundreds of individuals. Nests of prairie dogs and several social in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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