The livestock industry is a global market, where livestock in Western countries mainly include cattle, sheep, pigs, goats, horses, donkeys, and mules, other animals may predominate, such as buffaloes, oxen, llamas, or camels. Livestock and meat are produced, processed, and consumed around the world as are many industries. Being involved in livestock also means being exposed to risks that can affect profitability. There are a number of factors that can affect livestock production, meat processing, and purchasing, including weather, disease, the cost of animal feed, and changes in consumers’ diets. By the 21st century, cattle made up just over 1/9 of the biomass of vertebrates. It is estimated that the mass of livestock on Earth, about 100 million metric tons, is more than the mass of humans, wild birds, and land mammals combined.