Can my horse just eat the same food as the cows?
No. Cows and horses, while they can be “buddies” to some degree, should never share the same food. In some cases, horses and cows can be friends, if they can be fed separately. That’s why there is no food called “Large Four Legged Animal of Any Variety Feed”. There are a few reasons why horses need their own type of food: quality, digestibility, and additives. Some of the additives to cattle feed are poisonous to horses…as in death.
Some background first…. cows are designed to ferment a huge portion of their food first, which breaks down feeds into useful pieces as the feed makes it’s way through the cow. Horses, however, ferment their feed in the hind gut, towards the end of digestion. This means that cows can take lower quality food, with less nutritional value, and make the most of it because of the early fermentation. Horses and their hind gut fermentation mean that they need higher quality nutrients in different quantities to be of use to your horse.
It’s not just the quality of the nutrients, it’s also the nutrients themselves that make a difference. Cows and horses vary in what vitamins and minerals they need and in the quantities of those vitamins and minerals. Cow feeds contain much too much iodine for horses, and are missing some vital B vitamin quantities for example. Generally speaking, cows require “less” vitamin and minerals than a horse, and if that horse is exercising, gestating, or growing, those requirements will really fall short.
It’s not just vitamins and minerals requirements that differ, it is protein and fat amounts as well. The take home message is that cows and horses need different amounts of vitamins, minerals, fats, and proteins, and that is why their feeds are totally different.
Then you get into the additives in cattle feeds. Many include monesin and lasalocid, which are deadly to horses. Not even worth the tiniest risk. Also know that some feed manufacturers use the same equipment for different feeds, so cross contamination may happen from one cow meal to the next, and unfortunately sometimes from cattle feed to horse feed. This is one reason to hang onto feed labels in the case of a recall.
And really… do you want your horse to start mooing?