Parturition – control • Parturition requires myometrial contractions and cervical softening. • The myometrium is a functional syncytium (coupled by gap junctions) so contractions are coordinated. Contractions occur because action potentials cause Ca influx; oestrogen-primed myometrium shows pacemaker potentials, which initiate APs if they are large enough. Prostaglandins liberate Ca from intrac...

The objective of this study was to determine the pattern of nutrient flux across portal-drained viscera (PDV) and liver in ewes with varying numbers of fetuses. Catheters were placed in the hepatic portal vein, a branch of the hepatic vein, a mesenteric vein, and the abdominal aorta of each ewe. Plasma flow and net cholesterol, nonesterified fatty acids (NEFA), and glycerol release across the P...

Relationships between hormonal and metabolic changes around parturition and colostrum yield and composition were investigated in 16 Landrace x Large White primiparous sows. Blood samples were taken daily from d 105 of pregnancy to d 2 postpartum (with d 0 being the day of parturition). Colostrum samples were taken at the onset of parturition (T0), and then 3, 6, and 24 h later (T3, T6, and T24,...