What is light work vs. maintenance

I ask this question because I am going to try a new feed. My guy gets an 8oz cup of Intregrity Lite am and pm plus 14 pounds alfalfa/bermuda pellets split into two feedings. I want to discontinue the Integrity and start Equidae Alfalfa plus or the Coastal I haven't decided yet. But I was looking at the feeding calculator and their is a pound difference in maint. And light work. I work with him everyday for about an hour sometimes two but that's it for the day. Should I feed according to maitenance or light work? Or should I just start low and see what his body condition does? He is a little underweight I don't want to fatten his so much as build lean muscle especially on his back. We have been working on some back strengthening exercises.

ETA: Sorry I used the feed calculator and it was a 3 pound difference

I would go with the lower amount myself. If he loses a bit of weight, add the extra lb. If he gains weight, then you'll need to find a different feed that can be fed in smaller amounts.

I agree with luvs...

Start low and if you need more, add it. Ultimately, maint. Would be no work at all, a pasture puff and light work would be what you're doing, but IMO it's probably not enough work to really make a difference.

I'm willing to bet your horse would do fine on the maint. Plan.

Ditto the two above me :)

Toline lacking can many times be caused by a defiency in amino acids... aka protiens while he may not actually be def in protiens it could be the QUALITY of the protiens