Bioscientifica Proceedings

Summary. The processes of follicle development and puberty are closely related, and both are associated with maturation of the hypothalamic—pituitary—ovarian axis. Prenatal development of the ovary is independent of gonadotrophic stimulation. Beyond 60 days of age (postnatally), tertiary follicles develop and gonadotrophins begin to influence ovarian follicular development. Negative feedback regulation of pituitary gonadotrophins by ovarian secretions dev...

The capacity of pig uterine tissues to recognize and respond to maternal and conceptus signals determines whether pregnancy can be established and defines the environment in which embryonic and fetal growth occur. Limits of uterine capacity may be defined genetically. However, the extent to which functional uterine capacity approaches genetic potential may be determined, in part, by the success of organizational events associated with growth, morphogenesis and cytodiffere...

The Meishan pig provides a biological model with the genetic capacity to express a high prolificacy. This prolificacy can be partially attributed to a higher ovulation rate and a higher rate of prenatal survival at a given ovulation rate throughout gestation than in European breeds. Both early embryonic survival (factors inherent to the ovum and uterus, which occur before day 25 of gestation) and uterine capacity (factors inherent to uterine limitation, which occur from 3...