"A high grain diet in some humans seems to change bone structure. The reference was to Native Americans in the Midwest and skeletons showing changes in skull formation after corn became a part of the diet. There were enough skeletons found over a long enough period to be a reasonable sample to base the conclusions on."
I'm sure others saw this in an Applied Ethology post. It caught my eye as many horse owners feed carbohydrates as a main type of hard feed. I wondered if it had any impact on the number of bone conditions/injuries that we seem to see nowadays and whether our native ponies seem to suffer less because they are deemed not to require so much hard feed and therefore ingest less grain? The post also briefly mentioned that different species were affected more or less according to their climate (and metabolic systems).
Whatever, it's food for thought (Oh dear, that pun's terrible!).
Quite possible I think - grains have long been responsible for a calcium/phosphorus imbalance in equine diets, and certain grains are also high in phytates which may inhibit mineral uptake.
I wonder if any studies have been carried out on the effects of diet in countries where legumes (e.g. peas, beans, alfalfa)rather than grains are fed to horses?