This Call Of The Hen thing is interesting. From what I have read, there seem to have been two competing methods for selecting for egg production in poultry. The first ( I think chronologically) was developed and published by Oscar Smart. He was considered the top poultry geneticist of his day. His method involved trap-nesting ..or.. counting egg production by hens over a 3 month period. His work was published in 2 volumes I could find. "The inheritance of fecundity in fowls"
(1917) at
http://www.archive.org https://archive.org/details/cu31924003138710 Here is the 1921 edition (footnote), I like the pagination better :
https://archive.org/details/cu31924003077611 and in the book which I bought from the U.K., "The Burn-Murdoch Poultry Course". Which interestingly arrived with an ephemera piece of 1918 glazed window screen, touted to be the next big thing in poultry coop window covering.).
Then Walter Hogan showed up with his observational methods of discerning potential for egg production. Personally, I think Oscar Smart was the more well educated of the two. However, with the growth of more backyard poultry persons with lives
besides poultry.. trap nesting became a burden instead of a viable method. With the pressures of a busy life, who
wouldn't want to trade months of trap nesting and record keeping for just "looking" at a chicken. While most small poultry keepers today don't have time for trap nesting, Still I wonder about Smart's' method.
From the Burn Murdoch" book, Just a brief excerpt to outline it, "I have found in practical selection that the best period for the winter test is 3 months, starting either on the 15th of Oct. and ending on the 15th of January, or starting on the 1st of November and ending on the 1st of February. The former period for the earlier pullets, and the latter for the later hatched.".
The way Smart pulled this all together, so simply and thoroughly, with his descriptions of laying factors L1, L2 and Zero plus how they inherit. Very interesting. I also believe that some may have thought they needed to trap-nest for a full year as the pros were doing with the laying trials...when Smart proves such is not the case.
It seems to me that, in the end, the two system's
competition ( if one wants to call it that) was solved by the concept of
time management. In the modern world, it simply was much easier to "observe" the fowl, rather than trap nest it.
Best,
Karen
(footnote) By the time the 1921 edition was published, the young man ,Oscar Smart, had recently passed away from chronic ill health.