Dry skin on my Jersey

I found a patch of dry skin on the backside of my Jersey heifer. She did just come out of heat and shares her pasture with a 1500 lb Holstein heifer. Not sure if this contributed to the patch of unusual  skin I'm concerned about.  Here's a picture. Can someone please help me identify the problem.  She's acting normal and eats just fine.  

Have you considered a bit of soapy water?  You’re in a better position to get a good look at her than I, but in the photo it looks like maybe some dried mucous. They can excrete a bit of mucous (sometimes bloody) a day or two after estrus. She could easily have smeared it over there with her tail, I think...