Our next calf update will for our Adopt-A-Cow will be December 5th. Guess the height of our calf, Nyla, by November 29th for a chance to win a Dairy Fun Goodie Bag! Closest guess wins. Helpful info: Nyla is a Jersey cow which is one of the smaller dairy breeds. The average height for a mature Jersey is 46-48 inches. Nyla's birch height was 20 inches, and she is currently 2 months old.