Has anyone seen diet formulations that used to be in use when some of the older heritage breeds were developed and prior to our understanding of the chicken's nutritional requirments? As I understand it, if you go back in time further than a 100 years or so, diets provided to poultry were little more than mixtures of grains and possibly added minerals (oyster shell or limestone). The mixes of those times promoted growth by supplementing natural forages but by themselves were not nutrtionally complete. Guessing here that such formulations might occur in older publications concerning poultry. It is of interest to me when animal proteins started showing up in the formulations.