I am not up to writing an exam essay but I suspect raw greens may positively impact the gut biome as well as providing trace elements, vitamins and fiber.I am reading another old poultry manual, and have just come across a sentence that spontaneously triggered a question for us all (I used to have to set exam papers twice yearly ):
"Raw greenfood is the foundation for health. The failure to provide it has caused the deterioration of the modern hen and the commercial egg." Worthington. Discuss.
My guess is absence of greens in a chicken’s diet is therefore negative.
That said, the statement is rather overblown as surely breeding for production traits must have had a bigger negative impact on overall health, wellbeing and longevity of the modern hen, as well as keeping conditions.