Complex sentence: Due to their bulk and relatively small legs, cattle cannot roll over, so those that lay down and roll to their sides with their feet pointing uphill may become stuck and unable to rise without assistance, with potentially fatal results.
Split into simpler sentences: Due to their bulk and relatively small legs, cattle cannot roll over. Those that lay down and roll to their sides with their feet pointing uphill may become stuck and unable to rise without assistance, with potentially fatal results.