Complex sentence: Horses or their ova and embryos imported into Britain from Romania must be subject to a Coggins test for equine infectious anaemia prior to export, a protective measure which came into force on 3 May 2007.
Split into simpler sentences: Horses or their ova and embryos from Romania must be subject to a Coggins test for equine infectious anaemia prior to export. This is a protective measure which came into force on 3 May 2007.