Another snippet from Gilbert White:
“The natural term of an hog’s life is little known, and the reason is plain – because it is neither profitable nor convenient to keep that turbulent animal to the full extent of it’s time: however, my neighbour, a man of substance who had no occasion to study every little advantage to a nicety, kept an half-breed Bantam-sow, 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 shewed 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. At the age of about fifteen her litters began to be reduced to four or five;and such a litter she exhibited when in her fatting-pen. she proved, when fat, good, bacon, juicy and tender; the rind, or ward, was remarkably thin. At a moderate computation she was allowed to have been the fruitful parent of three hundred pigs: a prodigious instance of fecundity in so large a quadruped! she was killed in spring 1775.