$ORIGIN foo.
$TTL  100
@       IN  SOA ns1.tld.foo. hostmaster.tld.foo (
                2012030701
                900
                300
                300
                600
        )
@    300 IN NS ns1.tld.foo.
@    300 IN  A 172.16.143.197
ns1.tld.foo.    300 IN A 172.16.143.197

zone "foo." {
             type master;
             file "foo-zonedb.rr";
             notify explicit;
    };

options {
         [Your other options here]
         forwarders {172.16.1.1;};
}