This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
In treating this subject we shall be compelled, for want of space, to confine ourselves to giving only a general outline, and recommend those who desire to go into the finer details to that most excellent work, Sanders' Science of Breeding. There is no other one thing which so affects the value and usefulness of live stock upon the farm as does the selection of those to be used for breeding purposes; and a more judicious selection would enhance the value of the stock on many a farm today.
As to the best breed to raise, it is a matter of choice to each individual according to the use for which he intends them and the demands of the market. But whatever be the breed, select only sound, healthy stock. Never breed a mare because she is lame and unable to earn her keeping by work. Many, if not all, defects in the dam are transmitted to the offspring. Never breed a mare until near maturity. It is a habit of some farmers to breed fillies at two years of age, and then often to some inferior stallion because he is cheap. No mare should be served until three years old and not then unless well developed. Never breed an old, broken down mare. Select only such as are fully matured, well developed, vigorous and of kind disposition, and mate with a stallion selected with the same care, and you may expect a favorable result.