Your colors here are good, but your cow starts to get lost in the darkness of the trees in the background. Otherwise this is a good photo, the donkey does stand out a little more than the cow, but that is cause it is in the lead.
Nice capture of trainning and yes I would have to agree it does meet the challenge cause most would ask why are the chained together.
I was touring a cattle ranch in West Virginia, when I noticed this young cow chained to the donkey, I started asking questions and learned that this was done as obedience traing for a 4-h cattle show. As I watched the duo I could see that the donkey was in absolute control. The poor cow could not get a drink of water until that donkey got thirsty! I had hoped the photo would make the viewers want to know why they were tied together, but no one asked!
Darn cute shot! Very well done!!! Nice details and very good color. Chained together, eh? Who leads? Your title says the little grey fella, but I'd put my money on the cow, more bulk! 10 Rob the Swash