Maybe that smell you're noticing is attitude on your upper lip. If your neighbor's chickens reduce the value of your property, perhaps it was not worth what you thought to start with. I know I would not regard a home's value as lower because a neighbor had chickens any more than I'd regard it higher because said neighbor was a rich yuppie who owned a Ferrari. Minding one's own business is a lost art in this country. It used to be taught in elementary school....on the playground....by other kids. Now, little punks grow up thinking it's their "duty" to tell others what they can and cannot do. Ah, how useful a broken axe/shovel/pick handle can be at times.....
If an ugly, homely person moves in next door, does that improve or damage your looks? If a tall person moves in, does that make you feel taller or shorter? Rather stupid isn't it? The idea that less than $100 worth of chickens can lower the value of your home/property is preposterous. What if the Clampetts moved in next door? Goats, chickens, you name it....and enough money to buy everything you own and have plenty of money left. What if Bill Gates moved in next door and protested YOUR way of life because you're so far beneath him?