350. Late Gestating Sows, Particularly First Sows, Display Insulin Resistance.

Abstract Low-vitality newborn piglets are at increased risk of being overlain and are less able to access colostrum, substantially reducing their likelihood of survival. These piglets require additional care in the immediate postnatal period. There is increasing evidence that gestational diabetes in sows may lead to perinatal asphyxia which is hypothesised to cause foetal hyperinsulinemia and increased oxygen demand which in turn can lead to chronic hypoxia and vulnerability to intrapartum asphyxia, neonatal hypoglycaemia and mortality. Therefore, the aim of the present study was to determine the incidence of gestational diabetes based on indices of glucose of insulin metabolism in lactating sows. Gestating sows (Large white x Landrace) x Danish duroc) were housed under commercial conditions in a dynamic herd. At approximately day 109 of gestation, 145 sows and gilts were weighed, body condition scored and had backfat measurement taken using an ultrasound scanner. The following day sows had a single blood sample taken from the mammary vein for analyses of glucose and insulin concentrations and calculation of Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and Quantitative Insulin Sensitivity Check Index (QUICKI). The mean plasma glucose and insulin concentrations and calculated HOMA-IR and QUICKI and summary statistics are presented in Table 1. There was a large range in both plasma glucose and insulin concentrations and hence HOMA-IR and QUICKI indicating instances of insulin resistance. When the HOMA IR values were categorised according to the human values approximately 4.1% (between 2 and 2.9) and 28.3% (above 2.9) were categorised as mildly and severely insulin resistant, respectively. Interestingly, there was a dichotomy in the distribution of HOMA in gilts with 43% being optimum and 57% exhibiting severe resistance. Gestational and lactational performance of these sows and their litters were very good with total born alive of almost 16 and mortality of only 10%. Nevertheless, even in a robust sow herd almost a third of the sows could be classed as insulin resistant. Further research is required to determine the relationship between gestational diabetic state and neonatal piglet survival and performance particularly in gilt progeny. For image description, please refer to the figure legend and surrounding text.