I already had some un-decorated cows and decided the simplest paint scheme on a cow would be Black Angus. So I picked up a set of Woodland Scenics Black Angus cows at my local hobby shop as a reference.
Checking several shades of black paint I found Floquil weathered black to be the closest match to the reference set. I did not try to paint the eyes, hoofs and noses.
I added one of the Woodland Scenics built-up windmill sets at the end of the pasture that has the gate in the fence. The area around the windmill was given a tiny bit more green and soil colored ground foam and a few grass clumps to show some dampness there.
Once the cows were all painted they were placed in several groups around the pasture and secured with adhesive. I ended up having 16 adult sized and 4 calves for a total population of 20. These are the first figures on the layout.
Here is an overall view showing most of the ranch scene as an eastbound Western Pacific TOFC train passes by. Still plenty of little details to be added to the area but overall I am very happy with the results.