Testing for Remote Listener

Anyone know a good method for testing whether a remote UDP service is reachable - preferably without the use of netcat or similar tools? TCP-based listeners are easy enough to do a cursory test: TCP gives you a basic pass/fail on a socket open attempt. Thus, a test like:

      for HOST in ${SERVERLIST}
      do
         printf "Attempting service-connect to ${HOST}...\n"
         SOCKTEST=$(timeout 5 bash -c 'cat < /dev/null > \
                                   /dev/tcp/${HOST}/53')$?

         if [[ ${SOCKTEST} -eq 0 ]]
         then
            printf "Socket-test passed.\n"
         else
            printf "Socket-test failed.\n"
         fi

      done

Is a fairly quick way to ensure that (in this case) the guys who provisioned a system pointed it to reachable DNS servers (didn't fat-finger any entries in the DHCP zone).

Using the above method-type for UDP doesn't really work - you get false successes. The specific case I'm trying to verify is NTPD accessibility. Using ntpdate <SERVER> would be fine, but I'd need to do my tests like service ntpd stop ; <TESTS> ; service ntpd start. Could also use ntpq -c peers, but would really rather test servers individually rather than all at once. And, really, would overall prefer a generalizable method for UDP testing rather than having to do per-service test-definitions.

Any ideas?