Short answers, pulled from the story.
The domestic chicken traces its lineage to a single domestication event that occurred approximately 8,000 years ago in Southeast Asia. Genomic studies indicate this process began in what is now southwestern China, northern Thailand, and Myanmar through the collection of eggs from the wild red junglefowl.
Chickens were first utilized for cockfighting, a practice that formed part of the cultures of ancient India, China, Persia, Greece, and Rome. Large sums of money were won or lost on the outcome of encounters between two mature males before the transition to farming for eggs and meat occurred gradually.
China produces two thirds of the total global duck meat, amounting to some 1.7 billion birds. Other notable duck-producing countries in the Far East include Vietnam, Thailand, Malaysia, Myanmar, Indonesia, and South Korea, with France being the largest producer in the West.
Battery cages are often set in multiple tiers where several birds share a small cage which restricts their ability to move around and behave in a normal manner. These cages have been illegal in the EU since the 1st of January 2012.
A 2011 study by the Translational Genomics Research Institute showed that 47% of the meat and poultry sold in United States grocery stores was contaminated with Staphylococcus aureus. Furthermore, 52% of the bacteria concerned showed resistance to at least three groups of antibiotics.