No, it is not. Domain owners have the choice whether to secure their zones through DNSSEC or not. For domain owners that want to do so, they (or any party appointed by them as Technical Contact) must be able to sign their zones. Even though DNSSEC is not mandatory, we strongly encourage those domain that uses the Internet for critical data (such as banks and online stores) to adopt DNSSEC to protect against hijacking of traffic in the event of cache poisoning.
