Complex sentence: In addition to these fertile hybrids, there are infertile crossings such as the male Dzo of Nepal, a cattle-yak crossing which is bred for agricultural work-like the mule they have to be continually bred from the parent species.
Split into simpler sentences: In addition to these fertile hybrids, there are infertile crossings such as the male Dzo of Nepal, a cattle-yak crossing which is bred for agricultural work. Like the mule which is also infertile, they have to be continually bred from the parent species.