Your vet will be an important source of information regarding vaccinations, de-worming products/schedules, etc. for your geographic locale. It's always a good idea to have your vet visit with your mini when he is healthy, so he can get a baseline familiarity with your horse BEFORE he becomes ill or injured (hopefully that never happens, but we all know....). Good routine health care and proper nutrition can help ward off a host of evils.
One thing I did fail to mention when I posted last night, but is equally as important to what I did post is this. Feed companies/manufacturers set rate of feeding for each individual product as well, and these feeding rates are invariably expressed by weight (not volume, like 1 cup, 2 cups, etc., that is, unless they provide their own "cup" like Buckeye). Recommendations will be made for weight of feed in relationship to weight of horse. And while it's becoming a little more common, most bags will never mention feeding rates for a mini, though they might for a pony. More often feeding rates will be expressed in pounds of feed for an average 1000 lb horse at maintenance or moderate work and you will have to do a little math to figure what the feeding rate for a mini would be (and that requires having at least a guestimate of what your mini weighs).
Since many of my responses to posts get long, and sometimes complicated, I think I'm going to try a new approach. A "short version" for a succinct answer to a question, and then a "long" version which gives more of an explanation, for those who are interested in the whys and wherefors.
SHORT VERSION:
Each feed will have it own rate set for delivering nutrition/guaranteed analysis. While some feeds might require, for example, 2 pounds per day (maybe 4 or more cups per feeding) be fed, others might only require 8 ounces per day (1/2 cup or less). Similar levels of nutrients, but in wildly different volumes. Feeds that require LESS to be fed on a daily basis provide the same level of nutrition, but usually less calories per serving, and are frequently called "more concentrated".
LONG VERSION:
Some of the reasons behind this WEIGHT vs volume measurement are:
1) feeds all weigh different amounts. Weigh a single cupful of several different feeds, grains, etc., and you'll see what I mean
2) guaranteed analysis (all those numbers and percentages on the back of the bag) are determined by weight of the feed and not by volume.
Simply put, if you want your horse to have ALL the good things you bought the feed for (after all, you may have spent a great deal of time narrowing down your choice to that particular feed), then you MUST feed to manufacturer's recommendations for weight/activity level of your horse in order to achieve that benefit.
You certainly CAN feed less than manufacturer recommendations, but if you do provide LESS than bag recommendations, then your horse is no longer getting the full benefit of that feed. If you feed MORE than the manufacturer recommends, you're probably okay to a point. Many nutrients in excess will just be lost to excretion in the urine, but why p*ss your money away (literally!) PLUS there are nutrients, when fed in excess, which can reach toxic levels (selenium and vitamin A come to mind).
That being said, the caveat for miniatures is that many feeds, when fed according to manufacturer's instructions, will provide too many calories for our minis, therefore making them too fat. So you're darned if you do, and darned if you don't...Right? Not necessarily. There are viable options. One is to change feeds to one with more concentrated nutrients (that's why many folks feed their minis ration balancers -- lots of nutrition packed into a smaller package -- more bang for the buck nutritionally, but less calories). These are often the more expensive, premium line foods. It seems like they cost more, but in the long run they actually cost the same or less because you feed less of the product for the same amount of nutrition provided on a daily basis. The second option, if you really, really love the feed you are giving, but the manufacturer requires that you feed more than your mini can tolerate calorie-wise, is to feed less of it, but supplement with an additional/vitamin mineral supplement (these generally contain little in the way of calories).
BOTTOM LINE: Your mini has a need for a certain level of vitamins/minerals/protein per day. These are provided through hay, pasture and the addition of hard feed (when required). In the absence of hay/pasture analysis, many people look to the hard feed portion of the diet to supply the bulk of the vitamins/minerals because there is at least a tangible label on those which tell you what the feed is providing. However, it's important to remember that hay and pasture are providing nutrients, too, as well as calories. It's a balancing act for sure! Look to the manufacturer's feeding rate guidelines to tell YOU how much to feed YOUR mini of THAT feed, rather than looking to what your neighbor is feeding.
Robin C