boar may be allowed to serve from six to ten sows, but on no account more. The best plan is to shut up the boar and sow in a sty together; for when turned in among several females, he is apt to "ride" them so often, that he exhausts himself without effect.
The period of gestation averages from seventeen to twenty weeks, according to the age, constitution, &c., of the mother; young or weakly sows farrow earlier than those of more mature age or stronger constitutions. It is commonly asserted that three months, three weeks, and three days, is the period of gestation; but, from M. Tessier's observations on twenty-five sows, it appears that it varies from 109 to 123 days.
A good breeding sow will produce two if not three litters in a year, but two should be the outside number; for where she is suffered to have more, the pigs are not so fine or so many in number, nor can she suckle them so well. How many years they would continue to breed is scarcely known, as it is generally considered to be most advantageous to spay them in their second, or at any rate early in their third year, and then fatten them for the butcher, especially where there is always a stock of young sows to replace them; for after the just-mentioned period the litters are seldom so fine, and the animal herself deteriorates in value. Some breeders, indeed, only suffer a young sow to have one litter, and then immediately spay and fatten her, as the bacon is then supposed to be equally as good as that of an animal spayed in the very onset. This is mainly a question of choice or economy. An agricultural author of some repute states that "a sow is fit for pigging up to her seventh year, and many will continue to be so even longer. The more prolific, however, the animal is, the sooner does she grow old and her fruitfulness decay."
But they doubtless would go on farrowing for many years, for there are instances on record of sows that have produced as many as eight or ten pigs at a litter when in their eighth and tenth years. Selbourne, in his "Natural History," gives an account of a half-bred bantam sow, kept by a friend of his, more from curiosity than with any view to profit, "who was as thick as she was long, and whose belly swept on the ground, till she was advanced to her seventeenth year; at which period she showed some tokens of age by the decay of her teeth and the decline of her fertility.
"For about ten years this prolific mother produced two litters in the year, of about ten at a time, and once above twenty at a litter; but, as there were near double the number of pigs to that of teats, many died. From long experience in the world, this female was grown very sagacious and artful. When she found occasion to converse with a boar, she used to open all the intervening gates, and march, by herself, up to a distant farm where one was kept, and, when her purpose was served, would return by the same means
