I love the bit about the cockerels and hens. I wonder whether similar segregation was enforced upon the wingless variety of cockerel and hen.
Our
"Blue Laws" here are statutory but I have no doubt that they have their origins in the customary observations of the Puritans and Calvinists who pretty much ran things in earlier times. As Catholics, Anglicans, Jews and various and sundry other types of heathen began to make their presence felt here and revealed themselves to be disinclined toward observing such social conventions, the local or state Puritan/Calvinist power structures began to legislate various local religion-based customs.
This isn't restricted to the aforementioned Sunday closings. Another example would be the existence of "dry counties" where the sale of alcoholic beverages is against the law, usually just on Sundays but occasionally, at least in the past, at any time at all.
Note that these laws refer to the sale but not the consumption of alcohol. This led to the phenomenon of "brown bag" establishments where customers were allowed to bring their own booze (in a brown paper bag) to the particular restaurant or "club" and then buy "setups" into which they could pour the liquor they bought with them.
John