DNS: Dig returns different responses...

Hey everyone,
Okay, so I've been having some fun with the dig command, and wanted to dig my old school. Two questions came up from this. So I:

dig @8.8.8.8 +recurse njcu.edu ANY

and the result is about 8 records, including the SOA record. One of them is this weird TXT record, and the other is an MX and A record. The rest are auth servers which I'm assuming are DNS.

Now I know for a fact we have many subdomains..gothicnet.njcu.edu... web.njcu.edu.... etc.. why aren't those listed here? They all have IP's that are on the same IP range as the main site, njcu.edu. I can dig them individually, but why can't if I use the +recurse option see every subdomain under njcu.edu?

My other question is when I do a

 dig +recurse njcu.edu ANY

This uses the DNS my ISP provides instead of google's 8.8.8.8 What I've noticed is when I do this...I only get back like half of the results, I got before, but then I also get back in the "additional Section" of the response, AAAA records which I didn't get before. And if I do this same query again immediately after, I get even less results. Why is this? Shouldn't each query give you the same exact response no matter where you get it from?

Thanks guys

A recursive query (which by the way is the default setting in dig) has nothing to do with returning subdomains.

If a DNS server does not have the requested information when it receives a recursive query, it queries other DNS servers until it gets the information, or until the query fails.