There are many different characteristics between beef and horse meat, whether before or after slaughter, the most important of which is the color of the meat and its composition and all the chemical, physical, and sensory characteristics
Talking of visual or general inspection, horse meat tend to be redder than beef but not in all muscles, this is hinged on the type of muscle fiber and the use (activity)of the muscle and based on the amount of alfa-red fiber , beta-red fiber or alfa-white fiber which depend the amount of myoglobin and whether it is more oxidative or glycolytic (Gregory, 1998 - Animal welfare and Meat Science). Another difference is the lower subcutaneous and marbling fat in equine meat.
Equine meat looks more redder in comparison to bovine meat. It looks tender than bovine carcass. Nutritionally equine meat contain more protein and less fat in comparison to bovine meat. In taste equine meat little bit sweet but bovine meat not.
In terms of visual appearance beef meat is of dark red color with brownish tinge with apparent marbling while horse meat is dark red with bluish tinge with absence of marbling. In beef meat fat is of yellowish white color while in horse/donkey meat it is of white color with greasy consistency
Horse meat called chevaline is having many differences from beef. First and most important is the color. Chevaline is more dearker reddish-brown than beef because it contain 0.7% myoglobin, which is highest of any other meat. Also, HM is not having any marbling, intramuscular fat deposits like beef. It is lean meat. Fat of the HM is more grasy and yrllow in colour, and can be easily separated out from muscle part.