"Perhaps I should give her mineral vitamin supplement at recommended dosage, increase her beet pulp and just continue to top dress with the Fibre O."
That's what I would do. 8lbs for light work makes me wonder at the quality of the feed. The recommended amount is based off "how much do you need to get the appropriate nutritional value from the feed" nothing to do with weight. So supplementing vitamins/minerals you can feed the Fibre O solely according to weight and forget about the recommended amount.
So yes, get her a supplement and up her beet pulp then IF still needed add the grain as a weight supplement.
Give her say 2 lbs Fibre O and 2 lbs beet pulp for ex.
Thanks Yogi. I have to this point been doing exactly that - giving her full amount of supplement (All Phase 20), adding beet pulp and slowly increasing the fibre 0.
This is how I will continue for now.
I was scared to give too much beet pulp because of the high phosphorus but I think I could move up on that based on what people here seem to feed easily.
I would eventually like to get her down to one feeding per day once she's an ideal weight and that would be absolutely impossible with the Fibre 0 recommended amounts.