Any generic feed supplements produced from seaweed or kelp for coat conditioning and hair growth.
According to Horse-Advice.com:
“In the Orkney Islands, off the mainland of Scotland, it was noticed that sheep grazing on seaweed were generally in better overall condition and had more resistance to illness, especially coughs and respiratory problems such as COPD and SPAOD. This led to the development of specialised feed additives based on sea weed and kelp.
It appears that the reason seaweed and kelp may benefit horses and ponies is in both the combination of nutrients and the content of Algin.
It is the iodine content of the seaweeds and kelp used in an equine supplement that is most important.”