Earlier quoted context omitted.
Converting in US units, 10 to 12 acres should be enough? Maybe a bit more if you want well fed chickens (the trick is to let them go ham in your fields in between crops (my parents both farmed their peas this weekend and will probably plant salads behind next weekend, and in the meantime, the chickens enjoy the field). It's easier if you eat meat and know how to kill your chickens, as you can 'rotate' them out every…
The 12 acres figure is with trees and berries, as well as some decorative plants. Also people still steal chickens if its easy enough, so clip their wing and try to keep them on your property.
We do not eat meat really. Maybe at a restaurant, or some fish at home, but not really otherwise.
I could handle raising some chickens for eggs or otherwise as pest control when they are infertile. I used to tend to the chickens on my grandma's farm throughout my childhood. How many chickens for 5 ha of gardens+trees+berries, do you think?