Typically, a designation of R1-A would mean 'single residence - agriculture", R2-A would mean 2-family, such as a duplex. The caveat is that not all municipalities use the same coding. Check the key of the plat maps for your area. Never simply believe what the ZBA says verbally, get it in writing.I think that means residential and light agriculture. As long as you are zoned ag, I don't think they can limit you to a certain # of chickens. But if that's not true, don't get rid of the chickens because if you are grandfathered, it only lasts as long as you still have them, once you get rid of them you wouldn't be able to get them back.
Another tip is to never let a city employee on your property if they ask. When they ask, it means that they have no legal standing to enter. Politely ask them to leave or face a trespassing charge. Put up No Trespassing signs.
I like this one: