Complex sentence: In the 1870s John was manager of Turretfield's cattle raising venture, and with his two brothers carried on the Turretfield Stud in succession to Mr. Holland, and they bred many racehorses that achieved success on the turf.
Split into simpler sentences: In the 1870s John was manager of Turretfield's cattle raising venture. He was one of the three brothers who for several years carried on the Turretfield Stud in succession to Mr. Holland, and they bred many racehorses that achieved success on the turf.