I have a jersey/angus cross bull calf that we have been trying to wean for 4 weeks now. We started at 4 weeks old putting a couple handfuls in his mouth twice a day while still giving milk replacer..... He's a bucket calf. He's 8 weeks now and still doesn't want much to do with the grain, he eats a little on his own, then walks away. He does seem to be grazing fine on the grass down here...... Anything to worry about?