That's because '2016/10/03' is not a "full date time" - so SQL will assume you mean "2016-10-03 00:00:00.0000" and work from that. Hence, items added after midnight last night don't meet your criteria and aren't returned. If you want todays items as well, use:
SELECT * FROM userinfo WHERE [LoadDate]>='2016/10/01' and [LoadDate]<'2016/10/04'
Or
SELECT * FROM userinfo WHERE [LoadDate] BETWEEN '2016/10/01' and '2016/10/04'