How did the chicken achieve such cultural and culinary dominance? It is all the more surprising in light of the belief by many archaeologists that chickens were first domesticated not for eating but for cockfighting. Until the advent of large-scale industrial production in the 20th century, the economic and nutritional contribution of chickens was modest. In Guns, Germs, and Steel, Jared Diamond listed chickens among the "small domestic mammals and domestic birds and insects" that have been useful to humanity but unlike the horse or the ox did little -- outside of legends -- to change the course of history. Nonetheless, the chicken has inspired contributions to culture, art, cuisine, science and religion over the millennia. Chickens were, and still are, a sacred animal in some cultures. The prodigious and ever-watchful hen was a worldwide symbol of nurturance and fertility. Eggs hung in Egyptian temples to ensure a bountiful river flood. The lusty rooster (a.k.a. cock) was a universal signifier of virility -- but also, in the ancient Persian faith of Zoroastrianism, a benign spirit that crowed at dawn to herald a turning point in the cosmic struggle between darkness and light. For the Romans, the chicken's killer app was fortunetelling, especially during wartime. Chickens accompanied Roman armies, and their behavior was carefully observed before battle; a good appetite meant victory was likely. According to the writings of Cicero, when one contingent of birds refused to eat before a sea battle in 249 B.C., an angry consul threw them overboard. History records that he was defeated.How the Chicken Conquered the World | Andrew Lawler, Jerry Adler
I imagine that the chicken achieved such cultural and culinary dominance because they were delicious.