Apex domains cannot have CNAME records.
Question and response
Question
dig madhoster.com. NS
Answer
madhoster.com. 2 NS nserver1.madhoster.com.
madhoster.com. 2 NS nserver2.madhoster.com.
Authority
The response has no authority records.
Additional
nserver1.madhoster.com. 2 A 91.105.200.10
nserver2.madhoster.com. 2 A 91.105.200.14
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0