Bioscientifica Proceedings

Melatonin, which is synthesized at night by the pineal gland, is present in the cerebrospinal fluid (CSF), but its entry site and its role in this compartment are not known. Using several approaches, we tested the hypothesis that melatonin enters the CSF through the pineal recess, an evagination of the third ventricle. CSF melatonin concentrations are higher near the pineal gland than in the anterior part of the third ventricle, and decrease markedly (80%) after sealing of...

Summary. The progress in understanding the metabolism of the ruminant cumulus-oocyte complex (COC) from large antral follicles has progressed significantly in the past decade. In particular, new insights in the importance of lipid metabolism, ß-oxidation and its relationship to oxidative phosphorylation within oocytes have emerged. This provides opportunities for tapping into the potential yield of ATP from lipid metabolism, as ATP content is a major dete...

Summary. Important improvements in the management of sows have been made over the past 20 years in Europe and the U.S.A. Nevertheless, annual productivity varied between 15 and 25 piglets weaned per sow per year in France for 1983. Reasons for such a difference in productivity have been analysed quantitatively.Marked differences exist between herds in the genotype of pig used and in the age of puberty. Transportation acts as a stress...

Although the major source of relaxin in pigs is the corpus luteum of pregnancy, there is now evidence for relaxin gene expression and translation into protein in the theca intema cells of the preovulatory follicle, the corpus luteum of the cycle and the uterus. The theca interna cells retain their ability to express the relaxin gene and protein following ovulation. During the early stages of development of the corpus luteum, the theca-derived small lutein cells are the so...

Nutritional signals are detected by the central nervous system (CNS) and translated by the neuroendocrine system into signals that alter secretion of LH and growth hormone (GH). Furthermore, these signals directly affect the activity of the pituitary gland independently of CNS input. Insulin-like growth factor I (IGF-I), insulin, leptin and specific metabolites, such as glucose and free fatty acids (FFA)', are potential signals of the metabolic status to the brain-pituit...

There are many potential applications of transgenic methodologies for developing new and improved strains of livestock. One practical application of transgenic technology in pig production is to improve milk production or composition. The first week after parturition is the period of greatest loss for pig producers, with highest morbidity and mortality attributed to malnutrition and scours. Despite the benefits to be gained by improving lactation performance, little prog...

A number of lactation management strategies can be applied to reduce negative effects of lactation on post-weaning fertility. This paper focuses on effects of lactation length, Intermittent Suckling and Split Weaning on follicle development and subsequent oestrus. It is concluded that a lactation length of less than 3 weeks still leads to suboptimal reproductive performance in our modern sows. Further, both Intermittent Suckling and Split Weaning stimulate lactational fo...

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

Abstract unavailable© 2013 Context Products Ltd...

The control of reproduction in goats is interesting for technical reasons (synchronization of kiddings, adjustment to forage availability or to economy), and for genetic reasons (identification and dissemination of improved genotypes). The use of short-light rhythms leads to markedly increased production of semen per buck and prevents occurrence of a ‘resting’ season. Recent identification of a bulbourethral lipase in goat spermatozoa opens new perspectives in sperm ...