If your horse was getting a recommended 5lb (ish) of the Sr feed, and was fat, then a RB is a reasonable first choice of change. 5lb of many feeds is somewhere in the range of 7500 calories, but some can be 8500 calories. Swap that out for 1lb of a RB and you’re in the 1300 cal range - huge decrease.
It’s not about how much fat there is, it’s about the calories per pound, and how many pounds you’re feeding
I know they have high protein, but my horse is only getting a cup per meal, 2x daily. I am saving money, and my horse is staying fit. I have been feeding it for 2 yrs. Maybe b/c my horse only gets a cup per meal, it is not high fat?
Again, it’s all relative. You can have a 10% fat Sr feed, and a 10% RB (I don’t know if any are, just an example), and by feeding 10lb of the Sr feed, you are feeding more absolute fat, vs the fat you’re feeding in 1lb of the RB. 5lb of 10% fat feed is 750 fat calories (assuming 1500cal/lb). 1lb of 10% fat RB at 1300 cal/lb is 130 fat calories. But more importantly, it’s a difference of 6200 calories or more.
I have to trust my vets, b/c i am not a nutritionalist either.
Given how little many vets know about this, it is up to you do educate yourself