I personally would not want to walk around a farm at 1 week postpartum. I would be worried about germs as farms are naturally covered in animal poop and salvia. We love farms and recently went to a pony riding birthday party that included a petting zoo at a local farm. We wore our rain boots and brought trash bags to put them in so we could make sure not to get poop and dirty all over the car.
I think it's more about you than baby. Are you good to walk for a bit or would it be better to wait another week or 2. We have our own farm down the street and a couple fields of animals on our own so she's always been around animals
I would id just be mindful of sanitizing hands before touching baby