I would bet the larger calves may have been a bit thick and got stressed at birth.That would explain the slowness.A 100# snake is easy to deliver than a 75# bowling ball.

I don't like getting those little bitty 60 to 70 # calves as they don't seem to ever catch up to the larger but if your going to sell bulls around here anything over a 90# birth weight just as well be cut and sold as a fat steer because thats all he'll bring on a sale(with a few exceptions).

Our average birth weight on bull calves is 79#s and the heifers were 74#s..We don't weigh the commercial calves unless they are REAL big or REAL small.