Interwar recipes for chicken feed

[Perris]

What I'm finding most interesting this time I looked at it, is how uneven the consumption of several of the ingredients was:
The group eating the separated ingredients ate 35 grams of salt the first two weeks, 5 g the third week, 0 in the fourth and fifth weeks, 100 g the sixth week, 110 g the seventh week, 40 in the 8th week.

this is indeed interesting. But I suspect it is more 'effect' than 'cause' with growing chicks; their appetites would have been responding to the body's self-monitoring and -regulating systems, and the organs and other bodily tissues grow at various rates, so need different things at different times. Pica in a pregnant woman is the most obvious example today.

Having the same nutrients in every bite at every meal every day as per a pellet of concentrated feed is as far from natural or normal as it is possible to imagine. Before the last 80 odd years of human manipulation of their diets, there were millions of years during which birds evolved to eat what they could find in their environment, and that was the only route to survival and reproduction. That isn't wiped out in an evolutionary microsecond.

 

[Sic]

There were also some studies done in the 40's and 50's that showed that given all the ingredients of a balanced food chicks will eat what they need. A while ago I put out all the separate ingredients of a balanced food to test the hypothesis, and once they stopped thinking of these things as "treats" they ate what they needed.

Some day I'll isolate a group of chicks and do a real test. As I remember, the chicks that were allowed to select their own food grew faster and better than those on a mixed food with the same ingredients.

Reminds me of a study I read about, though the conclusion drawn was that animals will eat what they need to fix a deficiency, not prevent one. All I saved was a screenshot, doh