Highland beast

A nice silhouette shot and composition. A shame about the dust bunnies but they don't dissuade me from liking it

Cheers,
I did notice dust affecting the shot but still liked that image of the cow in the distance.
I'm quite new to DSLR photography.Need to keep the sensor /lens clean then?

It's not a big deal really and you could remove the culprits easily in photoshop or lightroom. They usually show worst in images like yours in the sky and when ever you use small apertures. A gentle clean with a rocket blower or similar may be enough to remove the partials of dust which are most certainly on the sensor. If it's more stubborn you may need to do a sensor clean if you feel up to it, check out the many vids online for advice.
Look forward to more of your images