have a look at the cartwheelholidays site. they specialise in farm stays and we have used this site before. we stay at Wringworthy holiday cottages near Looe which is about an hour from Exeter. they have loads of animals and the kids collect eggs, feed the chickens etc. worth a look as they are very geared up for younger kids. mine are older but still enjoy it though!
I'm looking for recommendations for farm stays for an animal obsessed 2.6 year old and a 5 month old for June. Preferably Devon but Somerset could be nice too. We stayed on one last year and the owners really got my daughter involved which she loved. They were also v geared up for families so we didn't have to bring much. That was in the peaks though. Ideas