Nutritional deficiencies are a relatively rare problem for a flock of backyard chickens, ducks or other poultry. Of greater nutritional concern are the following five easily avoidable mistakes commonly made in feeding poultry.
The common answer from chicken keepers when you ask them “what do roosters eat” is that they feed their roosters the same thing as the rest of the flock. This makes sense in backyard settings where the flock members typically vary in breed and size.
Poisoning is relatively unusual in backyard poultry, especially if you use common sense in keeping your flock away from pesticides, herbicides, rodenticides, fungicide-treated seed (intended for planting), wood preservatives, rock salt, and antifreeze.