They can definitely swim! 2010, our first time calving. One cow calved in the woods up from the watershed lake. We went out to check the calf, who was all of a few hours old, and she jumped up, took off, stumbled all the way down the hill and into the lake - where she proceeded to swim (more like dog paddle) towards the middle. 60 acre lake, 40 ft. deep, March 11th and the water was COLD. Yelled at Mr TC to go in and get her. He looked at me like I was nuts and took off in the Polaris to get the boat while I watched the calf, who by this time had made it to the middle, turned, and started swimming north. I could tell she was starting to struggle, so I dropped trou and jumped in. Yowza!!! Calf turned again, towards me, and I was finally able to reach her. She was so tired she didn't struggle and I got her back to the bank and carried her up the hill. I was barefoot and my feet were numb, so didn't realize I cut 'em up on the rocks. Got her to a leafy area and basically wrapped myself around her, rubbing her & trying to get her warm. Mr TC gets back w/the boat & doesn't see me or the calf, but sees my coat, bibs & boots on the bank. Minor heart failure ensues. He eventually hears me calling, banks the boat, gives me his coat, and carries the calf back to mama - who appeared to have no clue her calf was missing.
That calf is now boss cow, 12 years old and had her 11th calf in March. And she's still a diva!