The applications of intensive farming techniques to livestock are called factory farming, and include the following processes:
- Animals are kept indoors for part or all of the year, usually at very high density. The barn is kept warm by the collective body heat of so many animals in close proximity, and in very cold conditions buildings can be heated (though this costs the farmer). Less energy is lost as respiratory heat, so increasing NPP. In addition, animals can’t move much, so they don’t expend energy in muscle contraction. More of the food they eat is converted to useful biomass rather than being lost in respiration.
- Animals are given specialised, high-energy food for part or all of the year. This food has high nutritive value so animals grow quickly and can be sold sooner. The food is low in plant fibres (cellulose), so it is easy to digest and less energy is wasted in egested faeces. The food also contains mineral and vitamin supplements that the animals would normally obtain from fresh food and exposure to sunlight.
Factory Farming 2
- Animals are given antibiotics to mitigate the effect of infectious disease. The dense packing of animals makes it easy for pathogens to spread from host to host, so antibiotics are essential to prevent epidemics.
- Animals are selectively bred to be fast-growing , and they are slaughtered before growth stops in adulthood, so the farmer doesn’t waste any food, and earns profit early.
- When animals are reared outdoors their pasture is fertilised to improve the quantity and quality of grazing. This increases the animals’ energy intake at little cost.
These interventions all cost money, and indeed intensive farming depends on high levels of inputs to achieve high productivity.
But the gains in productivity should exceed the costs of the inputs.
Factory farms produce large amounts of animal waste, which often pollute surrounding water ways.
Factory farming also raises many ethical questions about the welfare of the animals.