A YouTube video of a farmer serenading a herd of cows with his trombone has gone viral.

Derek Klingenberg said he plays the song “Royals” by Lorde on his trombone to calm his herd of 380 heifers to make them easier to round up.

The video of Mr Klingenberg serenading his cows on a Kansas prairie has already recorded more than 2.6m views.

Watch the video below