At what age mares should be put to the stud has always been a question around which much controversy has gathered among breeders of horses; but whatever differences may exist in the matter of opinion, there can be no doubt as to the very general practice in vogue, which allows them to commence their stud career at two years old. This system of early mating is more prevalent among breeders of pedigree stock than among those who engage more especially in the production of trade horses. The latter recognize the physiological truth, that the highest development is reached where the nutritive resources of the system are devoted exclusively to its own maintenance, and not shared by the growing foetus, the main object being to encourage growth and development, and produce a horse with size, substance, and constitution.

Pedigree, and the glamour of family fame which attaches to it, too frequently prompts the indiscretion of breeding from babies, and the demand for special produce may, from a commercial point of view, justify such a course; but no one with any knowledge of the laws of life can doubt that to impose upon a mare the task of reproduction while actively engaged in building up her own frame, and to ask her subsequently to support her offspring, is a certain means of retarding her growth, if it does not also enfeeble her constitution. Those who care to take the risk of putting mares to the stud at two or three years old, should at least exercise some judgment in the selection of subjects for the purpose.

They should be forward in growth, and at the same time well furnished for their age, and in good condition.

They should not come to the horse until late in the season, and from the time when they are served to the day when they foal down, and onward to the weaning period, a liberal ration of corn, regulated according to the season, should be allowed them.

An open yard, with a well-littered shed for protection, and a run out in the course of the day if convenient, are the most suitable conditions for winter quarters.

While making these suggestions, the fact remains that the practice is a bad one at best, notwithstanding that examples of the contrary may be found in every variety of our horse stock. " That grand horse, Bury Victor Chief, for which Mr. Wainwright paid 1500 guineas, was the produce of Bury Daisy at three years old, and among the Hackneys such famous examples of the breed as Garton Duke of Connaught, Langton Duke, Langton Performer, Vigorous, Astonishment, Orange Blossom, and Dorothy Derby II were all from three-year-old mares.

Fig. 533. - A Shiverer.

" But of the huge total of animals so bred, those which have achieved fame in the ring and at the stud form a very small proportion, and lend no sort of encouragement to the adoption of early breeding as a general system."

It is in the interest of the race, no less than the breeder, that mares should not commence their stud career until they are four years old, when growth is being completed, and when the organs of reproduction have reached their full development, and the physiological energy of the system is well-nigh disengaged from the task of building up the frame, and can be more effectually devoted to maturing the foetus.

The great bane of the breeding-stud - hereditary disease - must be jealously guarded against, and in this connection much assistance may be derived from the careful study of family history.

It should, however, be kept in mind that many ailments are acquired as the result of accident, which in their outward form are indistinguishable from those which are hereditary.

Sprains, curbs, ring-bones, side-bones, roaring, whistling, string-halt, shivering (fig. 533), specific ophthalmia, and cataract are the most damaging of the many hereditary affections to which horses are liable, and whenever they appear, heredity should be suspected, unless evidence to the contrary is forthcoming.