1200 would be a big Jersey.

I have a beef cow here that will be 3 when she gives birth in the spring. She weighs about 700 lbs. Her mother weighed 1500 and her sire weighed about 1400. I dunno why she was so small but she is nice. I bred her to a Jersey bull {artificial } because the calf when born should weigh about 40lbs. Maybe I should go into the mini beef/dairy hybrid business.