Slanted? I'm not sure what that means...... You could guess, based on color, but it would be a guess. I have been able to tell on some by pattern, but that was only after the fact ("I think that one is a cock because the color on his head is more saturated and has well defined edges, compared to the others.") but there were other males without the same distinction. Did that make sense? You will be able to tell in a week or two on some and at three weeks, you should know on most of them. Be patient!