My ex keeps a small pack of cows, this is the biggest bull, probably "boss of pack", I don't know much about them myself, but bull screams like this occasionally, specially at night/early morning. Maybe because it is hot here so they are trying to sleep in shade in daytime and to graze at night. On this video he looks at me while screaming, if Im not there, he just screams without directing it on anybody. I can hear him screaming right now as I'm typing. Ex said its "bull thing" and nothing to worry about, but I want to make sure he not hurt or anything else like that.