The main difference between pastoral nomadism and livestock ranching is the type of animals that are being cared for. Pastoral nomadism will require the care of sheep, goats, and even camels. For livestock ranching, it is a bit different. Cattle would need to be raised. There are also some differences with their purposes. A lot of people who do livestock ranching would do it in order to earn a profit.
Those who do pastoral nomadism would do it for survival and sustenance. Pastoral nomadism is more common in Asian countries and in Africa. There are more people who do livestock ranching in America. These differences will make these two concepts easier to differentiate.
Nomadic pastoralism depends on the domesticated livestock and they can migrate in an established territory to find pastorage for their animals. The main difference between nomadic pastoralism and ranching is that pastoral nomadism is a form of subsistence agriculture whereas ranching is a form of commercial agriculture. Ranching does not necessarily involve livestock and it is generally treated as a secondary commodity. Nomadic pastoralism is an outdated technique and is almost non-existent in the present times.