Short answers, pulled from the story.
The word livestock first emerged as a compound term between 1650 and 1660. It merged live and stock to describe a specific category of domesticated animals. The definition has shifted dramatically over the centuries since that initial usage.
The Livestock Mandatory Reporting Act of 1999 defines the term livestock to include cattle, swine, and sheep. Other disaster assistance laws from 1988 cast a wider net to include goats, poultry, equine animals used for food, and fish designated by the Secretary. This legal ambiguity reflects the complex reality that horses are considered livestock in the United States.
Goats and sheep were domesticated in multiple events sometime between 11,000 and 5,000 years ago in Southwest Asia. Pigs were domesticated by 8,500 BC in the Near East and 6,000 BC in China. The domestication of horses dates to around 4,000 BC, revolutionizing transport and warfare.
The value of global livestock production in 2013 has been estimated at 883 billion dollars. This figure is in constant 2005 to 2006 dollars. The economic implications of livestock production extend further to downstream industry including saleyards, abattoirs, butchers, and milk processors.
Cattle produce some 79 million tons of methane per day. Livestock enteric methane accounts for 30% of the overall methane emissions of the planet. Livestock are responsible for 34% of all human-related emissions of nitrous oxide through feed production and manure.
It is estimated that worldwide 74% of livestock are raised in factory farms. These farms are characterized by densely confined animals. Consumers are typically against intensive livestock farming when surveyed.