My dog wont stop.......?

My dog wont stop barking,I have three dogs a border collie(female) a border collie cross(female) and a jack russell (male) he the worlds most annoying dog he barks all day for no reason,but im preg wiv my second child and dont want him keeping her awake like he did my first child,we av tried everyfin to shut him up,ya can tell he is my boyfriends dog because wen he tells him shut up he does it 4 a few mins but my boyfriend works full time,so i need the dog to stat listening to me,hes ist haha,but he really is driving me crazy? he is 5 years old now