This is a question we are often asked and my standard response has always been ‘well, it depends on the calorie content of the forage’, which has always then made me wonder about the relationship between forage NSC and digestible energy content.
In looking at 13 pasture samples from one farm it seems the higher the NSC content, the higher the digestible energy (calorie) content. The pastures shown here were all sampled between 11 am and 2 pm on the same day. They were all dried at the same time and all were analyzed by Equi-Analytical.
For interest I plotted the Digestible Energy (calorie) value against the pasture non-structural carbohydrate (NSC = starch + water soluble carbohydrates) content and while this certainly isn’t publishable data the trend is pretty clear for this particular set of pastures in that as NSC increases so does digestible energy… which makes very logical sense given the NSC is a source of calories so the more NSC, the more calories.
So perhaps my answer should be ‘yes, high NSC forages will make your horses fatter faster than low NSC forages!’. And therefore yes, it makes sense to feed a low NSC forage when you are trying to achieve weight loss or avoid weight gain in your easy keepers.
For some tips on feeding an easy keeper see https://feedxl.com/11-feeding-the-easy-keeper/