|Google books is an invaluable resource!|
I asked my trusty 18cLife Yahoo group, which led to a whole array of answers.
Among other things, I was pointed to a handy resource: an old book, now available online, titled The Discipline of the Light-Horse by Captain Hinde of the Royal Regiment of Foresters. I discovered that oats were, indeed, common provender for horses since at least colonial times, and I plan on taking time to read the entire book. Though written with an eye to the War of 1812, it contains many references to the American Revolution.
Something else I learned, though, was that Germanic settlers--Germans, yes, but also Dutch and other continental Europeans of varying religious backgrounds--were the ones who introduced the concept of large-scale farming with big barns and big hay wagons. The practice of farming the land on purpose (for "business," some said) and rotating crops were a curiosity to their British neighbors, who generally turned out their livestock to roam and graze, then herded them in as needed. Thus, the term "Cow Pens" where the famous South Carolina battle got its name was an actual area where pens were built for the periodic containment of cattle. Saddle and work horses might either be pastured or staked out to graze. Horses and cattle both do just fine on grass only, or hay with a bit of grain in the winter, but they'd need to spend a lot of time grazing because it takes a lot of grass to feed that large of an animal. Hogs and chickens or other yard fowl were also left to roam.
|Cattle drives were a thing long before the West was won|
The rich meadows and forests of South Carolina were actually considered cattle country at one time, and many savvy cattlemen were of African descent, whether enslaved or not, trusted with the keeping and care of herds. The Florida "Crackers" (as in, the cracking sound of the cattle drivers' whips) were also famed for their ability to work cattle in the harsh conditions of central Florida, through heat and torrential rains.
So, what did the colonial farmer raise crops for, if not to feed his livestock? The concept of the cash crop (tobacco, rice, indigo) dates back to at least the first settlement at Jamestown, and like it or not, much of the grains grown (corn, barley) went into grain liquor, especially the making of whiskey. (There's a whole discussion, in fact, on how the different spellings of whisky and whiskey denote a British-made product or an American-made one.)
I was able to find "provenance for my provender," in the case of whether to feed a favored saddle horse at least an occasional bit of oats, but it probably wasn't the norm for every farmer, especially not in the Carolinas.