Various breeds of cattle is not a revelation for the writer or the historical writer, however, these tidbits about the Devon Cattle breed might be helpful to you as a writer.
This race of cattle has been bred in England for a couple of centuries, and greatly admired for their many good qualities. They were imported from that country into the United States at the beginning of the present century; and are already increasing in numbers without any effort being made by the breeders to introduce them. For a large portion of our country they are better adapted than any other, being just the cattle for the hills. They are not excelled for their hardiness by any other breed; thriving where other cattle would starve, and yet showing care and good feed as much as any. For the yoke they have long been considered excellent; being docile, strong and quick in their motions. The quality of their beef is well attested by the price it brings at Smithfield market in London. When bred for milk, they equal any; as numerous cases of their producing from fourteen to nineteen pounds of butter per week will show.
They vary in color from a light to a dark red, with flesh-colored muzzles, with same around the eyes, the tip of the tail white, and sometimes their udders are white, but it should be nowhere else. Some breeders seem to prefer the light red color, while others prefer the dark red, but it is best to avoid either extreme. They are called by many the "little Devons," but it is not at all uncommon to find cows weighing from thirteen to fifteen hundred pounds, the bulls from fifteen to twenty-one hundred pounds, and thesteers often forty-five hundred per yoke. Duke of Hampden 832, at 36 months old weighed 2,030 pounds.
As for their milk and butter qualities, Mr. Wainwright, of Rhinebeck, N. Y., says he made 14 lbs. of butter per week from Helena 1712 (774 E); F. P. Holcomb, of New Castle, Del., 19 1-2 a week from Lady; Hon. H. Capron, formerly of Robin's Nest, 1l1., 21 lbs. in nine days, from Flora 2d, 120; C. P. Holcomb, New Castle, Del., in the summer of 1843, in twelve weeks, made from one cow 174 3-4 lbs. of butter, or an average of 14 lbs. and 9 oz. per week; during one week she made 19 lbs., and in three days 9 1-2 lbs. W. L. Cowles, Farmington, Conn., 16 1-2 lbs. in ten days. J. Buckingham, Duncan's Falls, O., in three months, summer of 1856, from four cows, an average of 44 1-2 lbs. per week, besides using the cream and milk in a family of seven persons. L. G. Collins, Newark, Mo., from the dam of Red Jacket, 98, 16 3-4 lbs. per week. Mr. Coleman, 21 lbs. per week for several weeks in succession. Mr. Hurlbut, of Connecticut, from Beauty (523 E), averaged 16 lbs. per week during June, 1850, when she was 16 years old. This is but a small portion of, those on my list as famous for butter.
What I also found interesting in this book was the names for the calves listed along with the year they were born. Helpful little tidbit if you want to name the family cow something other then Bessy.
The American Devon Herd Book
Here is a link from the Breeds of Livestock Web Page about the Devon Breed.