Yes there are more boys born this is a fact in all countries. Why that is? Perhaps nature knows men are more likely to die young, which they do, for all kinds of reasons.
Not a biologist so i could be mistaken, but from what i remember from high school Bio class it's because boys have XY chromosomes and girls have XX.
The X Chromosome is much larger than the Y chromosome, making it more likely for the XX combination to have genetic variations that make the fetus unviable.