Bioscientifica Proceedings

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

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

Studies of low birth weight offspring have a long history in pig science. These pigs have reduced growth potential and poor carcass quality compared to their higher birth weight littermates. In contemporary commercial sows with between 10 and 15 total pigs born/litter, between-litter differences in average birth weight appear to make the largest contribution to variation in postnatal growth performance, independent of numbers born. Low birth weight is a characteristic of...

In mammals, growing oocytes have characteristically high levels of RNA synthesis. After the initiation of meiosis, that is germinal vesicle breakdown, this RNA synthesis ceases. Although there is limited evidence for RNA synthesis by the zygote, significant amounts of RNA synthesis do not occur until a species-specific cell stage. In pigs, significant amounts of mRNA synthesis cannot be detected before the four-cell stage. There appear to be three qualitatively different ...

Buffalo are of high economic importance for farmers in several developing countries but reproductive performance is poor. A large proportion of heifers attain puberty at 3–5 years of age. A good quality diet supplemented with extra nutrients reduces the age of puberty whereas the effects of administration of exogenous GnRH or equine chorionic gonadotrophin (eCG) are equivocal. The incidence of anoestrus in buffalo ranges from 20 to 80% depending on season. Most buffal...

Prenatal mortality in European pigs is estimated at 30-40%, the majority of which occurs between days 12 and 18 after mating. Chinese Meishan pigs are prolific, averaging three to five more pigs per litter than do European breeds. Early reports into the fecundity of Meishan females suggested that their prolificacy resulted from lower embryonic mortality when compared with European females exhibiting the same ovulation rate. The preponderance of evidence suggests that ther...

The focus of this review is the physiological effects of undemutrition on ovarian follicle growth and the occurrence of ovulation in postpartum cows. Evidence suggests that moderate levels of underfeeding, before or after calving, may interfere with the mechanism(s) of final follicle maturation and ovulation, whereas more pronounced nutritional deficiencies may affect the mechanism(s) regulating dominant follicle size and the dynamics of dominant follicle growth and regression...

Bone morphogenetic proteins (BMPs) represent the largest subclass of growth factors in the transforming growth factor ß (TGF-ß) superfamily. BMPs have proven to be multifunctional regulators of a wide variety of biological processes in numerous types of cell and tissue. The role of inhibins, activins and TGF-ßs (which also belong to the TGF-ß superfamily) in reproduction has been studied extensively over the last 15 years. However, there were no reports on ...

Keywords: folliculogenesis; int raova rian control; pig© 1990 Journals of Reproduction & Fertility Ltd...

Abstract unavailable© 1982 The authors...