If you watch the plane’s left aileron you can see it “bounce” up as it grazes over the top of the cow.
It does look real, and there is very likely damage in the under wing area that we can not see due to the camera placement.
A better look can be had at http://www.youtube.com/watch?v=RPbX8sRfIak and then select “high quality”.
(You may want to turn the sound down first)
I also forgot to add, you can also see the passenger’s head slam forward at the moment the plane contacts the cow.