The meat industry are the people and companies engaged in modern industrialized livestock agriculture for the production, packing, preservation and marketing of meat (in contrast to dairy products, wool, etc.). In economics, the meat industry is a fusion of primary (agriculture) and secondary (industry) activity and hard to characterize strictly in terms of either one alone. The greater part of the meat industry is the meat packing industry – the segment that handles the slaughtering, processing, packaging, and distribution of animals such as poultry, cattle, pigs, sheep and other livestock. A great portion of the ever-growing meat branch in the food industry involves intensive animal farming in which livestock are kept almost entirely indoors or in restricted outdoor settings like pens. Many aspects of the raising of animals for meat have become industrialized, even many practices more associated with smaller family farms, e.g. gourmet foods such as foie gras. The production of livestock is a heavily vertically integrated industry where the majority of supply chain stages are integrated and owned by one company. Efficiency considerations The livestock industry not only uses more land than any other human activity, but it's also one of the largest contributors to water pollution and a huge source of greenhouse gas emissions. In this respect, a relevant factor is the produced species' feed conversion efficiency. Additionally taking into account other factors like use of energy, pesticides, land, and nonrenewable resources, beef, lamb, goat, and bison as resources of red meat show the worst efficiency; poultry and eggs come out best. Meat sources Global production of meat products Companies Among the largest meat producers worldwide are: JBS S.A. Tyson Foods WH Group World beef production Criticism Critical aspects of the effects of industrial meat production include hormone treatment such as steroids and the effect of consuming meat raised with these on human consumers, (see also Beef hormone controversy) animal diseases, e.g. mad-cow disease (BSE), avian flu, swine influenza (H1N1), avian influenza (H5N1), foot-and-mouth disease, some of which can spread to human consumers cruelty to animals is a common practice in the meat industry certain animal rights advocates and groups believe the production of meat is unethical and the industry should be abolished obesity - partially due to overconsumption of meat products human disease associated with animal waste, e.g. through E. coli cost of state services associated with the above including meat inspection and health care human