[Samba] Unable to Set TTL for Name Server Record

[lp101]

I noticed when Samba initially created a NS it gave it a ttl=900. If I 
delete this record from my zone and create a new one. It gives the NS a 
ttl=0. Attempting to set using Microsoft DNS tools does not take. Can 
this be done any other way? Using samba-tool? Thanks.

  Name=, Records=6, Children=0
     SOA: serial=481, refresh=900, retry=600, expire=86400, minttl=0, 
ns=samba4dc1.mydomain.local., email=hostmaster.mydomain.local. 
(flags=600000f0, serial=481, ttl=3600)
     A: 172.16.232.27 (flags=600000f0, serial=110, ttl=900)
     A: 172.16.232.25 (flags=600000f0, serial=110, ttl=900)
     A: 172.16.232.28 (flags=600000f0, serial=110, ttl=900)
     NS: samba4dc1.mydomain.local. (flags=600000f0, serial=479, ttl=0)
     A: 172.16.23.27 (flags=600000f0, serial=481, ttl=900)

Using Ubuntu 12.04. Samba 4.1.3