Gullivers Travels by Part 4 Chapter 8 Page 11

accident befalls a person whose wife is past bearing, some other couple bestow on him one of their own colts, and then go together again until the mother is pregnant. This caution is necessary, to prevent the country from being overburdened with numbers. But the race of inferior Houyhnhnms, bred up to be servants, is not so strictly limited upon this article: these are allowed to produce three of each sex, to be domestics in the noble families.

In their marriages, they are exactly careful to choose such colours as will not make any disagreeable mixture in the breed. Strength is chiefly valued in the male, and comeliness in the female; not upon the account of love, but to preserve the race from degenerating; for where a female happens to excel in strength, a consort is chosen, with regard to comeliness.