Fudeorca 
The Conqueror from a Dying Kingdom (Manga) Volume 1 

After a life seemingly devoid of meaning, a man reincarnates in a new world as Yuri Ho. Immersed in novel experiences and embraced by parents who shower him with unprecedented affection, his will to live grows like never before. The future that lies before him is a peaceful existence on his father’s ranch, breeding and raising birds to be ridden by warriors fighting distant wars.
His new home, the Shiyalta Kingdom, has enjoyed peace and prosperity for centuries, shielded by friendly nations that, like Shiyalta itself, were established following the collapse of a once-great empire. It seems no threat can compromise this idyllic lifestyle.
However, when the effects of a neighboring kingdom’s war throw Yuri’s family into crisis, he finds himself unable to stand by and watch.