Is this your tractor,or are you in the process of getting it? If it's yours,then you should know that JD wants you to run breakin oil for the first 100 hours.
There is alot of info on this subject if you search.
In my personal experience,I was going to put the breakin back in at 50 hours,but didn't. Dealer asked me how I ran my machine in those 50 hours, and when I mentioned it was at max rated rpm most of the time,He told me it's not necessary to go another 50 with breakin. So I went right to the JD Plus 50 II 15W-40.