Complex sentence: Breeding animals were selected in the 1960 from six counties in the eastern mountain area of Liaoning province, from then the herd has been developed and used to improve the cashmere herd throughout China.
Split into simpler sentences: Breeding animals were selected in the 1960 from six counties in the eastern mountain area of Liaoning province. The herd has been continually developed since then and used to improve the cashmere herd throughout China.