This post is just a suggestion! Not real data or benchmarks are been provided !
I was reading the manual page of resolv.conf. Yeap thats true, i am that kind of people that are reading manual pages before bed time.
man 5 resolv.conf
or alternative read this: resolv.conf.
I only use nameserver, domain and search configuration options on my resolv.conf, but reading the manual page,i ‘ve read about rotate option.
With this option our machine run queries with a round robin mechanism on our nameserver declarations.
That means that if you are using two dns cache servers in a big infrastructure, we can query both dns servers equally improving the load average on our dns machines.
If you have more, even better.
So give it a try