Bioscientifica Proceedings

Oestrus is the period around ovulation in which sows show a standing response for boars, thus allowing the boars to mate with the sows. The duration of oestrus may vary between sows from 24 h up to 96 h, which is not related to systemic oestrogen concentrations. The moment of ovulation after onset of oestrus may vary from 10 h to 85 h. Consequently, onset of oestrus is not a good predictor for the time of ovulation. A reliable prediction of ovulation time would be worthwh...

The sow, piglet and their environment interact together to determine whether or not a piglet will survive to weaning. The physiology of the mother and offspring, as well as the synchronized expression of their appropriate behaviours, is integral to piglet survival and both are governed by genetic and environmental components. This review discusses the multifaceted nature of piglet survival, concentrating on the environmental factors that pre-dispose prenatal (stillborn) ...

Cattle have recurrent follicular waves every 7–10 days in most physiological situations; an FSH increase is associated with emergence of the wave and LH pulse frequency determines the fate of the dominant follicle. To control oestrus with hormones it is necessary to ensure that either induced corpus luteum regression or the termination of a progestogen treatment coincides with the selection of the dominant follicle during the wave, to give a precise onset of oestrus and ...

Unlike in sheep, in which immunization against androstenedione causes mild and reasonably controlled increased ovulation rate, in similar studies cattle showed highly variable responses ranging from increased ovulation rate and fertility through to anovulation/anoestrus or superovulation. As a consequence, interest in manipulation of ovulation rate through this approach has declined and is now focused on immunological manipulation of endogenous inhibin following successful stu...

Declining fertility is a major problem for the dairy industry. Recent developments of Omics-technologies facilitate a comprehensive analysis of molecular patters in gametes, embryos and tissues of the reproductive tract which may help to identify the reasons for impaired fertility. Large Omics-datasets require appropriate bioinformatics analysis in the context of rapidly expanding and evolving scientific databases. This overview summarizes the current status of ruminant genome...

Summary. Kisspeptin is a hypothalamic neuropeptide that is critical for fertility. In virtually all species, kisspeptin neurons stimulate gonadotrophin-releasing hormone (GnRH) secretion and act as transmitters for sex-steroid feedback to GnRH neurons. In sheep, kisspeptin neurons are located in the preoptic area and the arcuate nucleus (ARC), with the latter involved in both oestradiol positive and negative feedback regulation of GnRH. In addition, sheep are ...

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...

Onset of puberty (sperm production) occurs at a much younger age (56-84 days) in Meishans than in conventional boars (120-180 days). Throughout postnatal development, Meishans exhibit markedly higher (two- to ten-fold) concentrations of serurn FSH, LH and androgens compared with conventional boars, and these high hormone concentrations are maintained at maturity. Increased gonadotrophin concentrations occur only in Meishan males, since concentrations in female Meishans a...

Abstract unavailable© 2009 Society for Reproduction and Fertility...

Seminal plasma proteins participate in a number of events important for fertilization and the establishment of pregnancy. As a result, attempts have been made to use them to enhance reproductive performance associated with several swine reproductive technologies. Inclusion of seminal plasma into cryopreservation and sex-sorting protocols improved sperm viability and membrane integrity and suppressed capacitation-like changes which are considered to be major challenges as...