Eureka! (though slightly off topic)
I've been moaning about how the science of poultry nutrition is more about economics than about health of the animal (how to provide the least amounts of the expensive ingredients and still get the maximum amount of poultry product) and therefore frustrating to research for those of us concerned about maximizing the health of our flocks by providing "good food" ...
While doing my daily reading of the Feeding Poultry book (http://babel.hathitrust.org/cgi/pt?id=coo.31924003011545;view=1up;seq=287) I came across a reference to a report titled Nutrient Requirements of Poultry, so thought I'd google that. I found the 9th Edition of this title (1994) available free online here ... http://www.lamolina.edu.pe/zootecnia/biblioteca2012/NRC Poultry 1994[1].pdf ... it is downloadable and searchable.
This report seems to be pretty thick reading ... but a useful way to answer specific questions about balancing various nutrients. I did a quick search for "calcium," for example. If I'm reading it correctly, it seems to state that calcium supplementation for laying hens can start earlier than POL ... but that if started too early it did increase the occurrences of "stones" in the urinary system of the birds. It also seems to suggest that "larger particle size" of the calcium supplement is beneficial, and that birds are very good at self-regulating their calcium appetite. I take all this to mean that having a feeder of oyster shell available to the flock, even a younger flock, is a sensible way to provide calcium. But of course that's not a recommendation, it's just an example of how I'm accessing and utilizing the information in this publication.
I'm not sure if a more recent version of this report is available free online, but I'll put it on the list of things to ask google.
Really going to enjoy the first book. Second one, hmmm, very heavy stuff. My eyes started glazing after a few minutes. Definitely a treasure for on spot look ups but not for "I think I'll read this book".
