I don't know exactly what the nutritional values are and it is going to vary some with the soil it was grown in and whether it is brand new freshly sprouted grass, or a later cutting from more mature grass.
Don't worry too much about it. Its a good staple. Feed lots of other things for variety too, and your tortoise will be happy and healthy.
Ok thanks @Tom, right now I feed endives, wheat grass, bok choy and mazuri, sometimes a bit of spring mix without the spinachs, I wish I could give more weeds but Im not sure if there are pesticides where I live so I don’t wanna risk it. Do you think it’s varied enough?