If you leave the flower on your rosebush, the petals will fall off after it finishes blooming, and a small red fruit will form and that is the rosehip. Rosehips form on any sort of rose shrub, even a hybrid tea or floribunda, but the hips most commonly used in foods and beverages are harvested from wild roses.
Rosehips contain a high amount of carotenoids and catchins, isoquercitrin all from the polyphenol family. Herbalist at the turn of century suggested we all drink a cup of rosehip tea daily. There seems to be something to that rosy advice. Those natural occurring chemicals have great antioxidant activities, a valuable source of vitamin C, containing as much as 20 times more vitamin C than oranges. Polyphenols also enhance the immune system, assists in weight loss, lower cholesterol, and beats up cancer cells and free radicals that disease the body. Rosehips also contain maltic acid.
For horses Rosehips make an excellent addition to their feed, encouraging strong and healthy hoof growth and used with other herbs Rosehips can help horses to return to health after illness. Not sure if the weight loss rule that is said to apply to humans follows thru to ponies but its worth a try for those tubbies.
1-2 tbs per day depending on size of equine