title: Improving the productivity of breeding colonies of Mongolian gerbils (Meriones unguiculatus).
abstract: The productivity of breeding colonies of Mongolian gerbils can be substantially enhanced by using as breeding stock only the 40% of females that exhibit vaginal opening before reaching 25 days of age. Early-maturing females are more likely to breed successfully on first pairing. The lifetime fecundity of early-maturing females is more than twice that of their late-maturing sisters. In those cases in which early-maturing females fail to breed with the first male with which they are paired, they (but not late-maturing females) can be mated with a second male with a high probability of success. Two-thirds of the early-maturing females that failed to reproduce following a first pairing became pregnant following a second. Only 11% of late-maturing females did so.
mesh_terms: D000367:Age Factors; D000818:Animals; D001947:Breeding; D005260:Female; D005298:Fertility; D005849:Gerbillinae / Q000502:physiology*; D012741:Sexual Maturation