Induced ovulation mimics the time-table of natural development in the stripe-faced dunnart, Sminthopsis macroura and results in the birth of fertile young

Abstract

Induced ovulation maximizes captive breeding success, increasing productivity and facilitating the contribution of otherwise infertile animals to the genetic pool. In marsupials, induced ovulation to produce fertile young is unknown. Here we present an induction protocol efficient in inducing non-cycling and non-reproductive females to cycle, mate, ovulate, and conceive. Ovulation was induced in Sminthopsis macroura using an initial injection of 0.06 IU equine serum gonadotropin (eSG)/g (time 0), followed on day 4 by 0.04 IU eSG/g. Using this induction regime, the timing of follicular and embryonic development mimics natural cycles and results in the birth of viable, fertile young. Response to induction is not significantly affected by animal age, making this protocol an effective conservation tool. We have established a time-table of development following induction, providing a source of precisely timed research material. This is the first induced ovulation protocol in any marsupial to result in demonstrated fertile offspring and to allow the reliable collection of known-age samples during both the follicular phase and the gestation period.