More than 2 dns - possible?

[admin@MikroTik] > ip dns set 
allow-remote-requests  cache-max-ttl  cache-size  primary-dns  secondary-dns

So I need more than primary and secondary dns. It is possible?

No, only two dns servers are possible.
Probably you can change primary,secondary dns configuration with scripts.
The most efficient solution to use stable DNS server as ‘primary-server’ in dns configuration.

Ok, thanks. Than I will use netwatch to controll gateways and set dns servers.