Pups can bark for a variety of reasons. The most basic form is that they use it to communicate with just about anyone and everyone! For example, other fellow pups or their Moms and Dads. Unfortunately, as any parent with a functioning pair of ears can testify, these barks can be incredibly loud and can ever hurt the ear!
As a result, most parents train their pups to not bark as much. This is always a good idea regardless of whether you are bothered by it or not – it helps reduce the number of false alarms (especially since barking is one way to get your attention) and shows consideration for the people around you who would otherwise be in earshot of your pup.
This particular Labrador Retriever seems to have its attention focused entirely on a cow outside. Cows are big creatures and can be pretty scary, so maybe he was just trying to scare it away to protect his family!
Feature Image Source: Saroj Pawar