Bioscientifica Proceedings

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...

Abstract unavailable© 1982 The authors...

Summary. Prolificacy has been defined as the number of viable piglets produced per year or per breeding lifetime. Prolificacy is influenced by age at first successful mating, ovulation rate and embryo survival at each mating, number of live born, viable pigs and the sow's ability to be successfully remated at regular intervals.It is concluded that under normal conditions of feeding and management nutrition will have a minimal influen...

Abstract unavailable© 1982 The authors...

Abstract unavailable© 1990 Journals of Reproduction & Fertility Ltd...

The mechanisms controlling the follicular growth continuum in the pig involve the interaction between local growth factors which are expressed throughout development and extra-follicular factors such as gonadotrophins. A large number of follicular growth factors, many belonging to the transforming growth factor-β (TGF-β) superfamily, have been identified in the somatic cells and in the oocyte. The relative importance of these intra-follicular factors varies wit...

Structural patterning and functional programming of uterine tissues are mechanistically coupled. These processes ensure anteroposterior differentiation of uterine tissues from adjacent segments of the developing female reproductive tract (FRT) and radial patterning that establishes uterine-specific histoarchitecture and functionality. Uterine organogenesis begins prenatally and is completed postnatally. Genes required for FRT development include Pax2, Lim 1<...

Abstract unavailable© 1987 Journals of Reproduction & Fertility Ltd...

In the ruminant ovary, synthesis and secretion of oxytocin begin in the granulosa cells of the preovulatory follicle and are markedly stimulated by the surge of LH and FSH. Luteinization of the granulosa cells results in a further increase in oxytocin gene expression, but translation ol mRNA appears to be retarded because the peak concentration of luteal oxytocin occurs later than the maximal accumulation of the message. Several hormones have been shown to stimulate oxytocin s...

Summary. Exposure of male and female pigs to elevated ambient temperatures can result in reduced reproductive efficiency. When boars and gilts are exposed to heat stress, respiratory rates increase to enhance evaporative cooling because minimal sweating occurs.During early pregnancy, gilts are especially susceptible to heat stress. Decreased conception rates and reduced litter size occur when gilts are exposed to elevated ambient te...