Complex sentence: Pigs remained popular on farms because of their ability to scavenge for food, and oxen remained the primary plough animal, although horses were used more widely on farms in the south of England towards the end of the 12th century.
Split into simpler sentences: Pigs remained popular on holdings because of their ability to scavenge for food. Oxen remained the primary plough animal, with horses used more widely on farms in the south of England towards the end of the 12th century.