Bioscientifica Proceedings

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...

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...

This chapter describes the application of functional genomic approaches to the study of imprinted genes in swine. While there are varied definitions of "functional genomics", in general they focus on the application of DNA microarrays, single nucleotide polymorphism (SNP) arrays, and other high coverage genomic analyses, and their combination with downstream methods of gene modification such as silencing RNA (siRNA) and viral and non-viral transfection. Between the initi...

In addition to endocrine regulation by the gonadotrophic hormones, the functions of the testes are regulated locally by paracrine and autocrine factors. Some attempts have been made to isolate cells from the testes of immature bulls and rams for investigation of cell function in vitro. However, most studies have used in vitro cultures of cells isolated from the testes of rats and a large variety of factors have been identified as potential local regulators. T...

Summary. Changes in uterine blood flow throughout pregnancy appear to be due to steroid-induced alterations in uterine arterial tone and contractility. Arterial contractility is a transient reduction in luminal diameter in response to nerve stimulation or to an alpha-1 adrenergic agonist, leading to short-term reduction in uterine blood flow. Tone is the pressure exerted by an arterial segment against an intraluminal flow (distensibility) and is considere...

Blastocyst activation, referring to the blastocyst acquiring the implantation competency, is the determining factor for implantation into the receptive uterus. It involves the process of embryonic cell differentiation to contact and initiate dialog with the uterine cells. Before the application of -omics approaches to this biological event, only the cellular morphological changes and a small number of molecules were known to regulate this process. This review aims to discuss t...

It has been suggested that the long-term reproduction of the sow is best served by minimizing weight and fat loss in lactation. Such a strategy would require only a minimal restoration of weight in the following pregnancy, which would be beneficial, since the greater feed intake and weight gain in pregnancy, the greater the weight loss in lactation. Feeding ad libitum should be practised during lactation while gestation feed intake must be held low. A relationship between...